Caramel that's a very nice looking rifle. It'll be interesting to see how well you are able to get it to shoot - mostly this will depend on the barrel quality and the bedding job. If you are able to get groups at 1000m that fit on a dinner plate, that'll be a darn fine long range rifle (essentially as good as a topnotch custom built competition rifle).
Light triggers don't necessarily help you shoot more accurately, though it can be quicker to learn how to shoot a light trigger well. Obviously too light a trigger is a liability to your scoring ability, one shot sent into the sky is more points lost than a light trigger will ever save you.
It is possible to learn to shoot a heavy trigger (3.5#) well, though it can take a year or so to learn how, and once you have learned how, it does take a couple of extra seconds when you are shooting a shot in order to be able to apply the pressure needed to break the trigger. F-Class rifles are often built with 100g - 500g triggers, the reason being that you can get a good shot away a bit more promptly than a 1000g or 1500g trigger.
If you want to learn how to shoot well at longer ranges, the best way to do so is to get out and do it. Even if you don't have an interest in competition shooting, if you do competition shooting for a year or two you will get to learn a *great* deal about reading wind, centring groups, loading ammo, etc. If you are near Quebec City, contact ATPQ/PQRA, who regularly shoot on a 600 yard range at CFB Valcartier
http://www.pqra.org/ . If you are in the Montreal area, contact the NCRRA
http://www.ncrra.ca/ , who shoot on a 900m range just west of Ottawa. In both the PQRA and NCRRA you'll find really great shooters who are willing and able to show you everything they know about shooting.