Yes, proper way to introduce the fish is to climatised the tank temperature, water parameter and to let the fish see the surroundings so that the fish will not shock
Should be ok to use cheapo UPS available in the market as the harmonics produced by the UPS is not strong enough to damage the wavemaker pumps because the pump motor used is small type and in water.
I think use airpump should be ok to circulate the water in the small tank for short period.
You can turn the skimmer on when dosing bacteria, unless you do not want too much skimate. Anyway excess bacteria will be skimmed if you switch on the skimmer later on.
Also depends on your tank heat load.
You may have MH lights, less efficiency pumps in the water or out of water, wavemaker, skimmers etc that will bring up heat and require higher chiller capacity.
For those using MH lightings, use this to automatically swithc off your MH lights when the temperature reaches unsafe limit. It would be a cheap DIY but will save you the hardship when your chiller breakdown while your MH lights are switch on...
If any sand particle stuck onto the cleaning surface, and if the magnet is very strong, the sand particle will scratch the glass surface. Use those cheapo glass cleaner using the blades is the best.