There are no mods for the game, other than that 1GB
third party texture mod. I played the Xbox version, but based on the first couple before and after screenshots on the website (in different resolutions, for some strange reason) I don't see that it makes much of an improvement.
There is a trainer a couple people have mentioned using to boost their stats and level, which should come up in a Google search.
The upcoming patch, expected around the release of FoV/DKS, is going to adjust the level dependence of combat, among other things. Once you get the hang of combat, though, the easy difficulty setting shouldn't be too hard.
I played a strength based duel wielding warrior, who sometimes started combat early to mid game with a bow, but didn't invest in any ranger skills. When DKS is released I'm planning on starting a ranger character.
So: warrior, mage or archer?Character OptimizationSave periodically, and/or before entering new areas, starting / completing quests, etc, and you will be able to recover more easily if you do happen to run into any bugs (or just entering areas too early for your level or wanting to try doing something a different way, etc).
A couple people have run into a problem when repeatedly quicksaving/loading indoors or underground (which could be rare or happen frequently, depending on the system), but there are not any common bugs that can be prevented by avoiding certain areas, or anything like that.
In general you should explore a particular area first and complete side quests before doing the main plot quests (which should be obvious).
The download version should already be updated, but I don't know where you would check for the version number.
I have not tried the PC version of the game, but on the Xbox the right stick (mainly used to control the camera) can be used to cycle through the opponents in range by moving it moderately quickly left or right when there are more than one opponent in range. I never tried using the crosshairs to manually select targets during combat.