Your tail wheel problem would probably be best solved by going to a tail skid instead. They do fine on grass and there's nothing to damage.

You can check your main gear alignment by putting a long straightedge on each wheel. It's easier with a helper so you can step back and see how the wheels are pointing. Both should be slightly in (toe in) to improve stability on the ground, but make sure they are both towed at the same angle. Once your main gear is straight, get your nose wheel straight for tracking and all you'll have to do then is correct for P-factor and bumps on the runway. A common issue with takeoff woes is having a landing gear setup that tracks differently than the fight controls do. As the plane gathers speed, there is a progressive change in how it handles. You'll never make a straight takeoff with those two systems not in sync.