In my view cutting the barrel if it's done well shouldn't affect the marketability - you would be selling a hunting tool and as you point out it is much more maneouverable and lighter, hangs up on stuff less ,and in my view should be all you'll ever need for moose deer or bear. (That's why I switched from a 300 Winmag with 26" barrel to a Ruger Frontier with 16.5" barrel). It may appeal less to a casual shooter but someone who knows his hunting guns would snap it up.
A good quality aftermarket trigger will not improve the intrinsic accuracy of the rifle - the action, barrel, and bedding quality are the main things that influence this- but it will make the shooter a lot more accurate as you do not have to squueze as much or as long with reduces the variation in muzzle position caused by the shooter.
For Timney triggers (or other aftermarket trigger) any good gunsmith should be able to bring it in. They do need a bit of fitting to match to the safety lever- made oversize. I ordered mine from Brownells.
www.brownells.com You will need to get an import permit (free in Canada) but its really quite straightforward.
cost is around $105 US plus shipping etc fees- figure around $180 canadian after all fees, exchange etc - a 4 to 6 week process in total. your Ruger trigger may have some value but frankly not a great deal - there are a lot of them out there. I would keep it as a spare part or on the off chance someone may want to buy the gun with the original trigger.
as an alternative a good gunsmith may be able to rework the Ruger trigger to give you a good pull. I can't really tell you who is good with these but perhaps other members could tell you who can in your area- I can't tell where you live form your info.