As far as raiding goes, I also don't feel very guilty about raiding AI resources and cards, but in the physical board game we almost looked at raiding as being too evil and rarely used it. I think might create a variant for the raiding so we can play the physical version more frequently. I think there's plenty of player interaction via blocking.
That's a difficult one. I understand what you mean, I know a few casual gamers that get turned off by games that involve direct conflict.
I'm not sure what to advise here because I feel raiding is an integral part of the game along with techs like Holographic Decoy which would be pretty useless without it. I would do your utmost to help players develop a 'thicker skin' about it or simply encourage raiders to raid 'fairly' stealing a little bit from each player (unless they're well in the lead).
Another complaint my friend had is that it's mainly a game about high dice rolls. So I might make another space facility that wants low dice rolls. I know there's one already but another one would be nice.
Firstly the game isn't really about rolling high dice, it's rolling the right
dice. Early on rolling doubles or a straight of whatever values tends to be more useful than simply rolling high numbers. I would advise your friend to focus on getting 1 or 2 tech cards that allow you to tweak the dice so you're more likely to get the numbers you need.
Secondly I don't think it's necessary is house rule an additional facility. The Colonist Hub is actually one of the most useful facilities on the board and helps mitigate bad dice. Add Asimov and you've got a sound strategy that is pretty much luck independent.