yes benidorm will still be open.its not like skeggy shuts for winter.you might get the odd bar shut for hols if that.but its still kicking.

I'd say base yourself in Benidorm. Out of season its accommodation will be cheaper than anywhere else due to supply and demand. Then you can drive out and see "real Spain" during the day and still have the nightlife in the evening. I've rented an apartment just for myself before now, they get so cheap once the kids go back. That gives you so much more room than any hotel does and breakfasts are so cheap in the local bars it just isn't worth getting tied into hotel mealtimes.

Where would anyone suggest for a single male - not a spring chicken but instead keen to hire a car and visit the real Spain!

If you want to see the real Spain, keep away from Benidorm and any other coastal tourist resort.
If you're wanting to pack as many places into the visit as possible, I would fly to Malaga instead and explore Andalucia because the major cities are closer together.

Sanji