I have watched up to the episode of "Q-Less" in season 1 and i'm just wondering if I could skip to season 3 (the war stuff) without missing too much?
The "war stuff" doesn't really start in season 3, that comes later in the show. The only differences between seasons 2 and 3 are that the Dominion reveal themselves and the USS Defiant is introduced. In fact, some fans (including myself) believe that season 2 is slightly better than season 3 overall.
I would personally advise against it, but if you really want to skip the first season while getting all the important background information for future seasons then I'd suggest watching these episodes:
(It's not a great episode but it introduces Grand Nagus Zek)
In The Hands of the Prophets
Then watch the second season.
If you still struggle through the second season then you can come back and we can provide you with a list of essential episodes from that year.