There’s no reason to record close to 0db anymore. Most of the times noise is not an issue with digital recordings. 

Recording between -20db and -15db should be great.

If you prefer the warmer sound of a used set of strings then no problem. Make sure that those strings can stay in tune, though.

Also some good advice for good recordings...

Paul Gilbert

"Tuning and timing
Recording comes down to two things: tuning and timing. Lots of unsigned bands I hear overlook timing. People think AC/DC, Green Day and the Ramones aren't great players because they don't play fast, but they have their timing nailed and their records are really tight and sound great as a result."

Adam D (Killswitch Engage)

"Tight fit
Half the battle is playing the part well. Remember the old phrase, 'You can't polish a turd'? If it sucks from the beginning, it'll suck at the end. There's no way around a bad sounding performance."

Marty Friedman

"Prepare and over-prepare, and then prepare some more. When you're done, practice everything over again, just once more. Then, by the time you get in the studio, everything will just flow out of you." ​