i want to put a bigger prop on and probably a 3 blade and I am concerned that maybe the torque of a bigger prop will tweek the sealed bearings.
Beware of attempts to improve a boat by changing the prop. This is not really something that is personal preference. There is a correct 2 blade
and a correct 3 blade prop for any setup. A sail prop is not the same as a power boat
prop. The size and pitch
should be optimized. The science of propellers is pretty well understood and as noted above it is a function of the engine and transmission not subject to a lot debate. Under sized and you give up power and over sized just adds extra wear and tear and usually no additional speed or power.
Any prop shop can do the computations for you for free. This isn't something you do just because you think one size may might be better. If you think switching from a folding two blade to another prop is something you want then that is OK, but guessing at the size can be an expensive and poor decision. If done properly there will be no impact on the drive shaft assuming the right prop was on the boat in the first place (might not be). You'll just need to measure the total prop clearance to help make the right choice.