Analog film photography and cameras

I just bought a cheap Epson v500 on ebay, so I could mae some digital contact sheets/convenience.

I think it's pretty much alright for that purpose, and stuff you posted looks good.
Surely that Fuji, and a 6x9 negative can deliver more than this, but I doubt you'll get much better with the V500.

any tips on decent/cheap or free scanning software and scanning techniques?

You could download a trial of VueScan and see if it's better than the Epson software for you.

Check if your software can do multi-pass scanning.
Scan at highest resolutions / basically crank settings up and see if it improves things.