Old Final Cut Pro 5

I'm a newb with FCP so sorry if this is silly....

I'm using Mac Pro, Mac OS X 10.5.6
2 x 2.8 GHZ Quad-core intel xeon

I'm currently stuck using FCP5. Yes, 5. I want to do nothing more than take three different mp4 videos, and put them into one video for playback. I would just need them all half size, put one in the top right, top left, and bottom left. These videos are only about 40MB each, but just importing them and trying to render says that it will take a couple hours, and never really gets done anyway. My videos originate from VLC and I'm not sure which format would be best to convert it to before going to FCP.

My question, is it possible that new codecs or video technologies make FCP5 so obsolete is really isn't usable with newer video formats? If I upgraded to FCP10 would this be quick and easy? I can't imagine that a 5 minute clip should take 3-5 hours to render just to work with it.

I don't know anything about fcp5, but if it takes ProRes I would try converting them to that for best performance.
Yes, using FCP X (10) would make this quick and easy.

ProRes came with FCS 2. The only weapon you have is AIC.

I don't know why, but the old Final Cut took some time to import MP4, so don't worry too much.

VLC is a nice player, but I'm not sure if I'd use it to transcode anything. MPEG Streamclip is more stable and faster.

If you want FCP X, you need Mavericks.