165mm is a pretty short crank for a freewheel application - how tall are you? Most mid-level cranksets will not "bend up" on you unless you're the Incredible Hulk, or if you're tossing your bike off cliffs. There's nothing wrong with the stock cranks - they're just heavy and the build quality isn't the best. Even with that, I don't foresee anybody bending them from normal riding.

Are you converting to a single speed or a 1X8 set-up? This crankset has a single chainring, so you will only have 8 speeds (as opposed to 16), and you will need to shorten the chain to get rid of the extra slack made for the links measured out to fit the stock 52T chainring.

The easiest way to upgrade the cranks would be to find a 130bcd square taper crankset and simply swap out the cranks and keep the stock chainrings. That way you can retain the front derailleur position and keep the stock gearing.

If you're not properly set up, tool wise, to assemble the bike in its basic, stock form, you probably don't have the crank remover tool required to remove the cranks arm.

A rubber mallet it NOT the tool required to remove square taper crank arms.