I am going to have both Minsc and Coran in my party. But there are some things I must be sure of first.

Minsc demands that I rescue Dynaheir, or else he will leave. The questions are then:
- How long can I go without trying to rescue her, before he leaves the party?
- If he goes, can I get him back later?

Coran is in the Cloackwood forest and is on a quest to kill some beasts. The questions are:
- How long can I go without doing his quest, before he leaves me?
- If he goes can I get him back?

This is very tricky. If I am to bring Coran with me, I must rush through the early game to get him on a low level. That means going straight to Nashkel and then Bandit Camp and then Coran. Along the way I must pick up Minsc. I just can´t wait taking him because then I will get him on a higher level and then his HP will be lower then if I had had the control over it. This may seem a little weird but he is to be my tank. So he is the one who shall soak up the damage, so he needs those extra HP.
So when we have gotten Coran we must first take care of Minsc´s quest, since his time is running out. So we travel to the Gnoll Stronghold, rescue Dynaheir (kills/leave her there by the way) and then we have Minsc for ever. But now we must hurry back to the Cloackwood Forrest and fight our way through to the beasts, and then we have Coran for ever also.
But will I make all this in time?

a question, why do u need to rush for Coran? You could easily get Minsc, then get Dynaheir (and do whatever you are gona do with her) and then go and get Coran.

No I can´t. The reason why many people don´t take Coran is bacause if you get him on a later level he will have used his thief skills in useless areas as pickpocketing and stealth. As I don´t need these thing I must hurry to get him.
If I get him around level 3 I should be okei.

i don't think there's that much difference between using detailed pre-knowledge or game engine queries to perfectly time NPC pickups and using shadowkeeper to re-arrange a few thief skills myself

Armen-he cant use SK as you dont get it for bg1, the only way this is possible is using bgt. Cant you use Gatekeeper though, and just do as Armen said, it isnt really cheating, its just making the most of the game.

Could also deliberately avoid Minsc, get Coran, do his junk, then return for Minsc...don't have to worry about Minsc's thieving skills!

No but my plans for Minsc makes it important to get him early. I am planning on having Minsc as a tank. He is the one who shall soak up all the damage. So he needs all the HP he can get. And if I don´t get him soon enough, he will have low HP.

but you are forgeting, when you get characters their levels are in comparison to your party members levels (up to a point) so Minsc wont be level one when you get him, he will be nearer your level.

Actaully, it might be better if you level Minsc and your party up, to a point, before going to get Coran. Since the Coran quest is not that easy; especially you should do it quickly. As RoSs_bg2_rox, NPC's level will be adjusted according to your PC's level. So when you actually get Coran, your party is good enough handling those wyverns.

yes, this happens to me alot, and that is why i have had to restart my game a few times, thats why i like making the whole party myself, noone complains aboot anything