Derek,
To answer your questions. Yes it is going to affect the way the plane flies. Maybe you can trim it. That will just depend on where your trims are already set, how much trim movement you have left, and how much trim you are going to need. Just be aware that when you take off you may not have enough trim to adjust the plane in the air, and if that happens you are going to have to manual compensate while you fly the plane. If you're nervous about it get an experienced pilot to help you out. If it takes too much then you may want to consider the repair.

Personally, if it were me I would do the repair before I flew it. But I can be a bit picky about my planes sometimes.

Hope this helps

Ken