My oil filler neck, the part that the oil cap screws into is fairly loose, i can twist a little and pull it out if i wanted, noticed when i was trying to take the cap off but it was on tight.
Is this something i should worry about?
will it cause any problems?
how can I fix it?
could this be why I'm seeing what seems like a lower than average oil pressure?

 

If you're talking about the tube that goes into the iron just drive it back in there with a wood block or something. It's an interference fit. Just make sure it's square when you drive it in.

No, it would have nothing to do with oil pressure. The worst it might do is seep around the base.

 

It can cause a vacuum leak though since the purge system draws air from the crankcase to the intake. Whenever I remove and reinstall these things, I always use a little bead of sealant to prevent air seepage.