I have a 2003 "pre-owned"

Scottsdale that has a solar charging panel. I have several questions:
1.) It appears to have been "factory installed" ( charging lite on dash) was this an option then?
2.) I haven't found any charge regulator and I am concerned about "boiling out" the batteries when I am parked outside. Is there a regulator?
3.) Is there a "cutoff" switch anywhere? (I haven't found one)
4.) I just installed new batteries as the original ones have 7 seasons on them and they were overheating during normal charge cycles (shorted cells). Anybody else have much experience with this setup?
Just curious I guess, OBTW Sears has Die-Hard deep Cycle marine cells on sale right now.
Cheers,
Dave