Spent another day studying simeng.txt and ended up updating the game and finalizing something to release. This is a bit technical, but an average computer user should not have a problem installing the patch.
This is Dynasty focused and uses default rosters to get more-or-less accurate results around the league. This does not mean that it only works for rosters, but it does mean that iy works best with rosters that have at default the stats distribution similar to that of default rosters (aka if you have already reduced fatigue in rosters, this will decrease it a bit more)
A note of warning though. NBA Live 07 uses -overall- stats to calculate game results and when results are known, the points are shared between players and other statistics generated and then shared based on player ratings. This means that there is no way to just simply make a player score 30 points. This means that the rest of the players in his team need to hold the ball less. Using default rosters, LeBron James does not score many points for a single simple reason - he has two other strong offensive players that get a share of the score due to NBA Live 07 algorithm. Since you cannot edit Primacy in game, you can tweak player ratings to your liking before applying the patch, the patch uses Offensive Awareness to calculate how much the player gets the ball (why? Because player gets the ball -only- in the offense, Primacy does not affect rebounds, steals, blocks etc)
Do NOT expect super realism here. It's strong improvement on original simulation engine and stats in dynasty, but I was merely focusing on dealing with assists and PF/C dominance. To get realism, you need to tweak players offensive awareness in the team in the roster/dynasty before applying the patch. The better offensive players CPU gets into their team, the less one player dominates their offense. It is just the way NBA Live 07 deals with it, there is no -team leader- or -leader duo- in NBA Live 07, and statistics are purely recalculated when a team gets a new star into the team, making them split their scores.
Anyways, what this patch does and how to install it, is follows:
1. SIMENG.TXT
Mainly tweaks assists. This ends up league leaders being around ~10APG.
How to install:
make a backup of your original simeng.txt in case you wish not to use the patch in the future. Then copy the simeng.txt from simeng folder in *.rar file into NBA Live 07's simeng folder
2. FATIGUE FIX
The patch redistributes Fatigue ratings in the league, making 0-99 ratings being changed to 0-84. This fix is necessary so that every player could get fatigued when playing the game.
How to install:
make a backup of your saved dynasty or roster file. Extract all files from ratingsfix folder into your roster/dynasty folder and execute FATIGUE FIX.BAT. You should execute this patch only once per roster/dynasty.
3. ROOKIE FIX
This patch is meant for rookies. You should -not- run it in the first year of your dynasty because the first year fatigue fix is already handled by FATIGUE FIX. However since FATIGUE FIX is only meant to be run once, ROOKIE FIX is used to make sure that NBA Live 07 new generated rookies would also have their Fatigue affected like the rest of the league has. This patch should only be used in dynasty (at the beginning of season every year after the first).
How to install:
make a backup of your saved dynasty or roster file. Extract all files from ratingsfix folder into your roster/dynasty folder and execute ROOKIE FIX.BAT.
4. MAIN FIX
This patch makes sure no player develops above 84 fatigue, and also redistributes Primacy around the league. It uses Offensive Awareness to calculate players Primacy (since in defence, rebounds etc the game simulation does not seem to take into account Primacy anyway) and improves guards and SF primacy while holding PF/C primacy down more. This results in guards being able to be among MVP contenders.
How to use:
Extract all files from ratingsfix folder to your dynasty saves folderThis patch should be run always when a team in your dynasty makes a trade, has a player injury and so on. Because of this, it is only really good for player-played dynasties and not only-simulated seasons (where constant updating would be a problem). This is so because NBA Live 07 automatically recalculates Primacy based on teams lineup changes. This patch should only be used in dynasty.
ORDER OF INSTALL:
IN FIRST DYNASTY SEASON
0. make backups of your roster and simeng.txt
1. place simeng.txt to simeng folder in installation directory
2. extract ratingsfix folder into your roster/dynasty save folder
3. run FATIGUE FIX.bat
4. run MAIN FIX.bat (and run it again after every ingame week or so)
5. enjoy the game
IN 2+ DYNASTY SEASON
0. make backups of your roster and simeng.txt
1. place simeng.txt to simeng folder in installation directory
2. extract ratingsfix folder into your roster/dynasty save folder
3. run FATIGUE FIX.bat
4. run ROOKIE FIX.bat
5. run MAIN FIX.bat (and run it again after every ingame week or so)
6. enjoy the game
UPDATING ROSTER ONLY
0. make backups of your roster and simeng.txt
1. place simeng.txt to simeng folder in installation directory
2. extract ratingsfix folder into your roster/dynasty save folder
3. run FATIGUE FIX.bat
(this only updates the Fatigue ratings so that every player has at least some fatigue decrease in game)
Example pictures:

Shows the improved assists per game (full season). Yes it doesn't show anyone in 10+, if you want more assists per game, increase float values in simeng.txt Assists section a little bit. I prefer current range since ingame the computer calculates assists for players differently from how they are calculated in real NBA, thus it's very hard to get 10APG even with Nash. Reason why Nash does not lead the assists even if he has 99 Offensive Awareness and 99 Passing is purely because Phoenix has alot of offensive players and NBA Live 07 calculates assists in share-basis, depending on every players ratings. And reason why Arenas is leading this is because Washington is vice versa, Arenas is one of the few there. This cannot be changed with any simengine update, but you can change it by changing players ratings in the team.

The only way to really get NBA Live 07 have players score in 30's is to have a team that has a lone offensive superstar in the team, like Kobe. Sadly the default rosters, as I explained before, have LeBron in a team that is way overrated by EA Sports, with Hughes and Ilgauskas rated as amazingly strong offensively, thus LeBron scores merely 22. If you want to improve this, decrease Hughes and Ilgauskas Offensive Awareness before using the patch.

The sweet MVP list. Arenas features here again since he posts great individual stats being a player for his team that he is. Sadly NBA Live 07 does not take into account team success for MVP Race (last 15 years the MVP has been won by a player of top-3 teams 14 times), but you see good guards and forwards here without forward/center dominence anymore.
It probably still requires updates and fixes, but it's ready to be released to people for testing. Just remember to back up your roster/dynasty before testing it out.
If you do not like the changes and the patch, just delete the patched simeng.txt and roster/dynasty folder and restore the ones you backed up. It works for me and I'm happy with the results, hopefully it'll increase your enjoyment of the dynasty mode as well. Sure, having to run MAIN FIX.bat after every trade/injury is troublesome, but I personally just do it always before running NBA Live 07 so it's never much of a problem.
I also need feedback, let me know how it works for you.
DOWNLOAD:
http://kristovaher.pri.ee/nbalive/simeng_patch/chris_simulation_engine.rar