Maybe take up golf?
There is no way that topping up oil should cause a gear issue. Unless you have disturbed the linkage under the cowling.
Or have you just checked them at the same time and infact the controls were clunky already?
Are you putting it ingear with \ without the engine running? in \ out of water? How did they perform the last time you tried? Was any work carrid out in the meantime?
Too many questions and not enough info.
Go with the golf!
Rob
Solenoid for the starter, not sure about tilt and trim, unless that goes through the same unit.
Check all battery connections are as clean as can be, esp. under the cowling.
R
Welcome!
Sounds like a pain in the a&£e!
Oil reservoir not sump, but if the lid blocks the pickup you will melt your pistons to the bore. Get it sorted!
I have something similar that I have in a peli case and bigger 4Ah battery as I want it powered for days but not from the boat battery due risk of drain. Peace of mind when left on mooring or on trailer away from home certainly.