As noted, the turbo versions are not just the non-turbo versions, with the added turbo.
1) Your engine will work at lower RPMs, without the turbo. But, not well, and you will not be doing long-term good to your engine.
2) Keeping the turbo clean and operational is a matter of maintenance
. I know, because I suck at this! Run the heck out of your turbo, on a regular basis. Yanmar
recommends using their Turbo Wash to keep it clean. Their recommendation? "once a week". Seriously.
3) Removing the turbo is a 1/2 day job, as is putting it back on. I've done this twice. The turbo can be cleaned when you take it out. Do NOT pry on the vanes. The turbo spins at 70,000 to 80,000 rpms!
4) You can buy a rebuild
kit for about $150. ANY turbo shop in the world can rebuild
it - these IHI turbos are common on cars all over the world. YOURS has been modified to the Yanmar engine, but it is essentially the same as all of the others. Not interchangeable, but similar.
Repeat #2 as often as you can remember.