If you want to race, you will need to wax to gain the real time advantage that advanced waxing offers.
I am not savvy enough with wax selection and best techniques to wax to an advantage. My ability to feel an effect from waxing is gone after one run regardless. I've never had a ski fail due to lack of wax - and my skis rarely get waxed. Ptex is designed to be pretty good. So wax is pretty low on my priorities.
Realistically, most people won't notice whether a ski has been waxed without a stopwatch or some race measure (racing a buddy?).
Edges are a different issue. On hard snow, edges might need to be worked on daily. At least frequently for a race ski. Even I can really feel a difference from sharp edges. If you get your skis tuned up in a shop, they will probably wax as well. Great! But don't get a wax without the tune.
I've had edges rust over the summer so tune at the start of the season. And store with a block between the skis to preserve the camber.
Eric