I'm looking for rebuilding advice as I'm repairing my engine after a timing chain failure

2007 RXT STAGE 2: I'm the original owner of this ski (85 hours now)

I replaced the ceramic S/C washers with metal before ever riding it

Installed Stage 2 kit at around 10-15 hours +/- (Runs 8100+/- RPM)

Timing chain broke at moderate engine speed, not full throttle

I removed the engine yesterday and have it partially disassembled

VALVES: I pressurized the cylinders –
EXHAUST valves are bent / Intake valves are not
Which valves should I buy? Supertech, OEM ???

Any chance of piston ring lands pinching the rings?

CRANK GEARS: Crankshaft & Balance shaft gears are OK- How di I remove the large crank sprocket to get at lower timing chain sprocket to inspect it ??

FLYWHEEL BOLTS Should I upgrade to Part # 295501043

’08 SUPERCHARGER OILER: Should I upgrade to Part # 420856875

TIMING CHAIN: Any preference, or use the OEM part # ends with -042??

EXHAUST MANIFOLD: Rear flange is partially torched away. Is there another year exhaust manifold that’s preferred?

Any other suggestions/advice would be appreciated

Thanks everyone !!