I have a FSA Vero crankset with a 48t crank. I need to find a 52t crank so I can have more speed on my single speed. Will any crank with a 5 bolt pattern fit? Thanks!

You need just a chainring, with a matching BCD of your current crankset.

What's your current gear ratio? It's cheaper and easier to change gears using the rear cog instead of the front chainring.

I'm fairly new to this so thanks for bearing with me. I have a 48t chainring, and a 17t freewheel. I would love to go down to a 15t freewheel though.

here is what I'm working with.

Yeah, changing the freewheel is an easier and cheaper alternative.

You're on about 75 gear inches right now, which actually nets you 20mph at a cadence of 90RPM. This is not slow.
Why do you feel the need to gear up?

If I were to recommend changing the freewheel at all, it would be a 16t freewheel. About 80 gear inches. 21mph @ 90RPM.

I pedal out a lot, and I've been riding with guys with 21 speeds and I would like to keep up without my cadence going crazy.

What cadence do you spin out at? Even 48/17 nets 27mph at 120rpm.