New 2084, New to Cubs in General

[Unseenthings]

Hi everyone, thank-you for all the valuable information found here thus far. Sam has provided many threads that I have read, maybe too many in that I now have confusing information swirling around. If you don't mind me asking old questions, I'll get my needs straight on one page.
My Toro Proline suffered a gearbox failure, and was too expensive to fix, so while I waited for used parts to turn up I went looking for a suitable replacement. I needed 54in of cutting width, and I didn't want tinfoil box store junk. A 2084 turned up on CL, and after reading on here it seemed it was a well received model. For $500 I got a basic machine, no PTO or 3 point. Good plastic. It's running on one cylinder, a exhaust valve stuck, bent a pushrod, PO pulled the pushrods out, loosed the sparkplug and parked it. I grabbed a set of complete used heads off 'bay and a gasket kit. Hoping throwing a head on there and sealing it back up will finish the year out. It's got 640 hours on it, and a CH18 which I'm guessing should be a CH20? Which I could make a CH20/2 with a carb swap? Might do a teardown over winter.

So in closing, any counters to my ideal on repair?
Conflicting information on what oil to put in the engine and hydro?
Where are these cooling fins that attract grass that I'm suppose to clean out?
Rear end mounts look good, do I still need braces if not doing any pulling?
Grease the zerk on the drive shaft coming out of the engine, and something about CV joints I think?
Rev engine before shut off.
Anything else anyone wants to add, I thank you for your time.
Cheers
Brian
PS, in Central IL, and will probably be for sale at some point if anyone is that interested.