- how sturdy are the mounts?
PLASTIC
!!!
- could I do short exposure (2-3 minutes), or longer exposure)
astrophotography with a DSLR on the end?
DOUBT THAT YOU COULD AS IT'S ALT/AZ. FOR 2-3 MINS YOU'RE GOING TO NEED AN EQUATORIAL MOUNT.
- comparison with the PRO series?
CHALK AND CHEESE!
- The system is labeled as Auto-tracking (Alt-azimuth), any ideas on how well it tracks?
NO IDEA! BUT CERTAINLY NO GOOD FOR SHORT EXPOSURE ASTROPHOTOGRAPHY
MINIMUM PACKAGE FOR THE KIND OF IMAGING YOU WANT TO TRY MIGHT BE AN ED80 ON AN EQ3 MOUNT, MOTOR DRIVEN IN RA. THAT WILL BE A LOT MORE EXPENSIVE THAN THIS SCOPE THOUGH.
ALL THE BEST
DOUG