I've heard that Osama was trained and funded by the CIA during the Soviet-Iraqi conflict.

This particular question has been addressed here in the past, so while there is room for more info, I'd encourage you to check out the FAQ (To give you the TLDR though, whether Osama bin Ladin was funded by the USA essentially comes down to what side you take based on the evidence, but there is no paper trail linking them.)

Yes.

This may be breaking the twenty year rule, but it's the only example off the top of my head.

The KLA was armed by the US and NATO in 1998-1999. The US in 1998 deemed the KLA to be a terrorist organization in 1998.

The proof was found by Milovam Drecun, and can be seen in his two books (both of which are in Serbian) as well as him recording it in his documentary on the Kosovo War (he worked as a military reporter). He documented (read video taped) finding packages in KLA possession which were marked as provided by NATO/US.

A number of POWs also admitted to having been trained by the US military in Albania, and having been given instructions to open up a 5 km buffer zone between Serbia and Albania in the south to allow for entry of ground troops (known as Operation Arrow).

The books and film by Milovan Drecun is all that is coming to mind now, though numerous witnesses at the ICTY attested to this. You just have to be willing to go through hundreds if not thousands of hours of court proceedings.