I will be a bit more specific in my answers:
Answer #1: Should work just fine, assuming it is the length you need.
Answer #2: Try it and see for the cost it should be good
Notes:
If it messes up the antenna SWR (Which as someone suggested can happen if the antenna is NGP) then a Ferrite Bead Choke at the SOCKET end of the cable may help, Radio shack sells these, they simply clamp on or you can get some from a ham radio supply like dxengineering.. Make sure they are the right physical size, you can also use 2 or 3 one behidn the other.
Second: Before you put it into service use an Ohm-meter to insure that it is not shorted (Center pin to Nut or threads
And that the cable is solid (Center pin to center hole, Nut to Threads.
A friend worked for a well known radio company's "Authorized service center".. They ordered a bunch of cables, pre made, from this very high quality radio company.. Every cable was shorted, both ends EVERY CABLE They had to re-make all of them... Umbical for my Towed's Lube Pump... Just one end was shorted.