In regards of your second question, you can easily edit this yourself:
Step 1. Download "EditSF". http://www.twcenter.net/forums/showt...-Array-Editing
Step 2. Now go and start a new campaign and save it at turn 1.
Step 3. Open EditSF and open the save file you just saved (usually located in C:\Users\<your username>\AppData\Roaming\The Creative Assembly\Rome2\save_games )
Step 4. Navigate to the table shown on this screenshot. You'll see two "20" numbers near each other. The upper 20 is the unit cap per army. The 20 below that is the navy cap per fleet. On my screenshot I've already edited the unit cap per army to 41 which is the max stable cap you can have without the game crashing so you can put this to anything between 20 and 41.
Now just hit save, close the program and load your game. You only have to do this once at the beginning of the game.
Some words of caution:
* Do NOT edit navies above the default 20. Anything above that will crash the game.
* You need a pretty good PC to handle armies these big, might be a good idea to lower visual settings a bit. The game might slow down from time to time due to the engine having a tough time processing all the troops. This is especially noticeable in sieges when CA's not-so-good pathfinding "shines through".
*You will have problems with the supply systems default values. They're not balanced around army sizes larger than 20. You'll be seeing lots of famined regions and AI factions constantly in starvation. You'll have to either buff the regional supply flat values across the board, the supplies generated from buildings and/or the consumption value of each kind of army-stance. You can also simply remove the supply system altogether.
* I've been unable to get these large army-sizes to work in coop/head-to-head campaigns with DeI. Some DeI script or something is causing desyncs to happen after 5~ turns in. But it works just fine in single-player as I've tested it for roughly 250~ turns.
* Get ready for a tough time! Fights with 15 000 vs 15 000 are a lot bigger and more chaotic than the standard DeI fights and unless you're spamming the pause-button to give orders along the frontline, you'll be taking lots of losses (which is more fun and challenging in my opinion). You will have to reinforce your garrisons with extra troops because the default garrison has little to no chance to beat an army with 41 units.
Hope this helped!