Re: air filter
I think what you are asking is if it matters what kind of filter you use. You can use a paper element, foam element of any quality element. What is important is that it fits.
You didn't mention if your filter didn't mate up to the carb or if your bike frame prevents the filter from from fitting.
For interference from the frame, you can saw your intake manifold into 2 pieces and connect them with an automotive heater hose. That allows you intake manifold to flex, so the carb can move to either side of the frame.
If the air cleaner simply will not mate up to the carb, you can get an automotive valve cover breather element. You can rig something from PVC pipe to attach it.
Use the site search. Search on "air filter" and check what others have done. You can also search on "air cleaner" or "intake". Learn from other members that learned the hard way.
“You're only young once, but you can be immature as long as you like" -Unknown