Need advice on a compressor I picked up

I just picked up a used Husky 60 gallon 7hp belt drive air compressor. I'm sure its not a true 7hp. Its 10.3 scfm @ 90psi. Label shows 240, 15 amp and is currently wired with the 4 prong plug shown below. I plan to use my 240, 30 amp dryer outlet, but the outlet is a 3 prong shown at bottom.

Question 1)
Is there any reason I can't just switch the compressor plug to a 3 prong to use my existing outlet?

Also, the compressor did not come with a valve, filter, or pressure regulator, Its jus plumbed with a quick release, pictured below.

Question 2) Any advice on what parts, (size, style, brand), I should use? Best place to purchase?

Thanks guys
-Rob