1.- - - - -YES!

2.- - - -NO!

3.- - - - -Less noise, less wear from hammering of the components if the clearance is too loose (most likely) or less chance of burned valves if they're too tight due to valve seat and valve face wear.

4.- - - - -Shame on you for not doing routine maintenance. Valves need to be adjusted at least a couple of times a year unless the vehicle never gets driven!
LOL!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!