300+ games of pudge, maybe 100-150 of those are roaming. Just got to 5k with a lot of roaming pudge actually.

What's your MMR? It's a lot easier for people to give you advice when they know what bracket you're at.

Should I buy my own wards? I NEED the vision, but

You answered your own question. Pudge needs good vision to function, and you know that. If you need to get wards, get them.

What can I do when all missing?

Get wards down. If you think they're farming split up you can try going blind into their jungle with a buddy from your team. If you can't, just pull or jungle with tranqs or something.

If my team is being unresponsive with the stuns, how can I guarantee hooks?

You miss 100% of the hooks you don't throw. SVG just missed 90% of the hooks he threw... just try hooks anyway, learn to read how people are going to juke when you cancel your hook animation.

Starting items:

First build: tangoes wind lace mango clarity smoke. I do this when I think getting kills is dependent on hooking only (i.e. I can't really walk up and rot). More mana items because I'm less likely to be spending a lot of HP on gank attempts and suiciding.

Second build: tangoes boots clarity smoke. This one's for getting level 1 kills with offlaner around the 0:00 mark/hardcore aggression at beginning of the game. Generally I will just suicide to neutrals after attempting a lv1 kill and taking a lot of dmg with this build.

Notice there's a smoke in both of my starting builds. You need smokes on pudge. He's a roamer that depends on killing, so he can't really just sit and zone like ogre can. If you miss an early kill because you walked past a ward, your impact is going to be a lot lower.