The games default control scheme is garbage. If you have the GOG copy of the game it has some custom schemes that you can load in the control menu that are more modernised. The game is extremely clunky still, but with a modern layout it's less of chore to work with.
Hacking is a stat one MUST invest in. It has a large affect on the game and it's a core theme to the series.
Research isn't an essential stat for the most part, but there are key points in the story where you need research stats. These points will often throw cybernetic modules at you to upgrade Researcg with... DON'T SPEND THEM ON ANYTHING ELSE! You won't need much anyway to get to the games required stat. However, certain weapons and items require research to use, and some of those items are really potent later in the game. It's worth considering.
Energy weapons and certain "exotic" weapons are only useful against specific targets (and there are 2 exotic weapons that default to harm the user, which is just retarded). Best stick with the good old pistol/assault rifle and shotgun as they are all versatile and useful troughout the game (the Ass Rifle is a beast when modified and you have plenty of ammunition).
The more esoteric a weapons use is, the less use you'll have for it. This is pretty shitty as there are a lot of esoteric weapons.
SEARCH EVERYTHING! Them damn cybernetic modules (akin to ADAM in Bioshock) are scarce enough on higher difficulties.
PSI abilities with the PSI amp is fun, but it's best to go all in or not at all. If you run a PSI build, get yourself enough stats to wield a pistol as, unlike most games, the pistol is quite potent throughout the game, especially if you manage to modify it. If this is your first time playing the game just skip PSI... it's like a built in "hardcore" feature that makes the game extra difficult.
You'll fucking hate ninjas.
You'll fucking hate Engineering (early parts anyway).
If you hear something that sounds like a broken C3-PO, keep the fuck away from it.
My personal preference of play is to join the NAVY, get a wrench and arm myself with a pistol, then pump stats into hacking and cyber affinity as core stats, with Maintenance, Endurance (only 3 pips in Endurance) and Modify as secondary stats but only up to the point where I can max out a weapons Modifications and repair a weapon from a quality of 5 to 10 with one repair module (beyond that is overkill).
Once you modify your weapon, don't dump it, as the upgrades don't carry over to other weapons, even identical ones.
"ARE YOU.... ONE OF US?"
Aw fuck, I guess I'm going to re-install it now too.