That's not always true, a lot of the point Loma spots are "finger crevices" train wheels and NRAD come to mind, and usually spots off point Loma can encompass 45-60 feet on the ledges, to well over 100 if that's what you desire
Correct. If going on a boat charter, be sure to find out the dive locations first. Being that you are only OW, you'll technically need to avoid the deep spots below 60'. Some boats check your cert. In addition to the day boats Humboldt (Waterhorse Charters) and Lois Ann, there is the Marissa. For overnight trips, the Horizon is great.
Unless you love cold water, you will need gloves, a hood and booties; NOT tropical thin ones. Temps at depth along the coast are generally in the 50's all year round, occasionally dropping into the upper 40's, or possibly topping 60. Surface temps can be in the 70's, so there is some variance. During Nov and Dec, barring El Nino effects, temps at depth should be in the lower 50's and surface in the 60's.
La Jolla Shores is probably the most forgiving spot to dive in So Cal. On days when the entire south coast is blown out, the Shores can still be dived. La Jolla Cove is far less forgiving, but probably a more interesting dive for you on a good day. So check conditions.
La Jolla Dive, and other ops, have dive guides available for hire.
Diversteve gave some good advice.