- I reckon there's no item highlighting like in Fallout 1 using mods right?
- I also doubt there's something like Fallout sfall's combat control to play companions during battle, right?
- I still don't quite get the fatigue system: I have 15 fatigue, I cast Fireflash which based on its tooltip should cost exactly 15 fatigue, but after using I have -2 fatigue and I'm knocked out -> most likely due to having 2 buff up which drain fatigue
- Is there a way to prevent companions from rushing ahead? I can use "Stay close" but once enemies are in sight everyone just blindly charges ahead
- Is there a way to immediately display the unique name of a NPC without having to go through the dialogue to unveil it, similar to P:ST or Fallout 1? I know it adds immersion, but having to talk to every NPC just to be able to finally see the name is rather tiresome
- Is there a reason why Virgil doesn't heal other companions?
- Why to HP/fatigue potions restore next to nothing for companions?

- Is there a way to prevent companions from rushing ahead? I can use "Stay close" but once enemies are in sight everyone just blindly charges ahead
IIRC F5 does that

- Why to HP/fatigue potions restore next to nothing for companions?
This may have to do with their magical/tech aptitude. Tech chars will get reduced effect from magical potions

I've never seen such a thing. I've never come across that either. That's exactly right. Your FT is based on your CN (constitution), and updates in real time, every 10 seconds. It can't go any higher than 6 points recovered at a time (for which you need a CN of 17 or above).

Any buffs or other continual spells will drain your fatigue at a set rate, depending on the spell. Casting an instant spell will expend the cost of the spell all at once. If at any point, your FT goes to or below 0, you will faint until it recovers.

I'm assuming you're playing in turn-based rather than real-time. If so, you have two options: the non-cheating one is to drink/use a fatigue restorer as one of your actions; the cheating one is to wait for your FT bar to refill in real time, which it will continue to do even if you're in the middle of a battle. As gnarbrag said, the F5 button tells your companions to wait this one out. Get into the habit of hitting it as soon as the battle starts; and then if you do want them to join in, hit F2 to give them permission to attack.

Note that if you're not using the very latest patch (2.0.2), then any attack your companions make will reduce the XP you get from the battle. This is one of the reasons I only ever bother with companions for storytelling purposes. If you hover your mouse over their tile (on the left side of the screen) you will see your companion's name and basic info in the black box under the hotkey bank at the bottom of the screen. And a lighted ring will appear around their feet.

If you left-click on their tile, you can talk to them. If you right-click, other options (such as looking at their stats, having techies build stuff, etc.) will appear. If he detects that their TA (technical aptitude) is too high, he won't bother with spells. Buy him bandages at the general store. Lots of bandages. He puts points into the Heal skill, but it takes him a while to get good at it. (And unless you took the Educator background, or upgraded to the latest patch, he'll never become so much as an apprentice, much less a master.) Quite possibly for the same reasons. If you have tech-based companions, consider investing in either Healing or Herbology. (Remember that Virgil is slowly investing in Healing as well.)

Also, stock up on Greater Healing and Greater Fatigue Restore potions for your non-tech followers. And possibly learn Minor Healing, which will get surprisingly strong as your MA goes up. (But don't bother if you plan on going tech instead.)