In most RPGs, it doesn't matter what's more important - you can take all the time you want to care about minor quests and errands, as the main story only continues when you actively trigger certain key events.
This brings me to one point that I sort of hate. If you get a quest telling you that it is very important to do something very quickly... every second person telling you that it is very urgent... that you mus hurry... that the world will end if you don't manage to do it in time.... and then you can wander around, solve ten other quests and after that still continue with the 'very urgent' quest.
Neverwinter Nights 2 starts like that. I skipped a lot of quests to complete the urgent main quest. This was very exciting... until I found out that you have all the time of the world to solve every quest on your way. No matter how long it takes you. There should be some point where you fail... just to keep the tension up, to keep it exciting, meaningful if you do or skip the other quests (you can still do them later on).
I also hate time limits. Especially when you have to play the optimal path to be able to do it in time. It should not matter if you stand around for an hour (afk and forgot to pause the game) or if you walk the long way around the forest instead of the direct path (unless it is quest related). You should be able to stop for shopping for example without having to look at your watch.
Not exactly sure how to do it right... But I think if you have these 'urgent' quests that there should be the possibility to fail them if you start and complete too many side quests on your way. Maybe fail if you travel to (very) far away places (not if it is only the next village in the opposite direction for example, that should be ok). But it should definitely not be a timer counting down in real time that decides if you fail (exception would be if the timer is very generous... like you have 10 days... and you can do it easily in a few hours).
