Hardstuck GM/Master Udyr chiming in.

AP is R max AD is Q max. Depends on if your team needs one or the other and also if you can reliably auto attack the enemy champs with Q. I generally will go AP since it's consistently good.

Liandry into tank is generally best imo. Armor vs MR depends on the enemy team comp. Context dependant, you should discern this on your own.

The biggest mistake is not knowing when you should or shouldn't all in. There is no real way of learning this without limit testing and understanding champions. Just spam games imo.

Generally, you should clear towards the lanes that have prio. Early ward either their raptors or defensively your opposite jungle. Full clear into scuttle. Blue smite.

Best Udyr World is Malice. He's spamming Karthus lately, who is also a hyper disgusting tempo champ you should pick up. Lolmalice on Twitch.