Carb and intake questions

So I have a 1973 yamaha gt80 that I just got running today but still have alot of issues to work out so I am hoping you guys can help me out a bit. My first question is their is a nipple on the intake with a vac line going into the motor its snapped off at the intake. Is that something I can cap off or does this line serve an important purpose?
Next question is on the carb their are two nipples one that the fuel line goes to and a much smaller nipple under that I am unsure what thats for I was thinking it was for the oil injection that is uninstalled? Anyway when I leave it uncapped and lean the bike over fuel comes out of it. Is this something that should be capped or is their something that should hook to it?
Next question is after I rode it I parked it in the garage and noticed that the line coming off of the bowl was pouring fuel im assuming that not normal?

Any suggestions to help a noob would be great and if anyone needs pictures just say the word. Thanks

So I wasnt in the mood to rip the carb apart today haha so instead I tossed the correct plug in, added a little bit of 2 stroke oil, sea foam and started her up. It actually revs and doesnt stall out!!!!!!!!!!!!!!!! So I ripped on it a bit and I had it to about 41 not to shabby. It still feels like it loses power in the mid to higher rpms and blows a tonnnn of smoke in the high rpms. It also dumps fuel out of the hose on the bowl when I shut it off so I am guessing like you said the float is either out of adjustment or just not floating. Anyway about it this is a fun little bike.

Another complete noob question. I pulled the carb checked it out the float floats it seemed level the needle looks good and clean but when I shut it off it still dumps fuel out of the overflow when I lean it over thats not normal is it/?

This thing is really starting to get on my nerves. The carb is spotless and everything looks great I have set the floats about 855 times. It seems to either want to flood and dump fuel out of the overflow or it seems fuel starved and keeps stalling. I ended up setting the float to 22.5mm which is within the specs so wth is the issue? I am really starting to get frustrated. Its a ton of fun to ride but it seems like it just falls on its face at high revs and truth be told it needs about 10 more hp. Anyway any help on why I cant get this float to work would be great.

Why was my two stroke carb question moved to minis? Just because its a pit bike sized bike?