First, warming your balls is not an effective birth control method. You may kill some sperm by heating your scrotum, but you’d practically have to set your “nuts a blaze” to avoid the potential of getting a woman pregnant. Then, your following questions wouldn’t even matter because you’d be in the hospital.
But anyway, I can’t think of anything you can do short term, to make your penis larger. Now I have tried the supplements you can find at gas stations. They did help to engorge my penis, at least I think. It’s could have been a placebo effect. As far as delaying ejaculations, short term. They do sell creams and condoms that have desensitizing agents in them. I have also used these in the past. The downfall, I once ended up having sex for 4 hours without cumming. The blue-balls I had later were atrocious. Though the woman did enjoy it, she was also a bit taken back by this. A woman wants their man to cum, it shows them they have satisfied their partner. So it can actually hurt a woman’s ego if you don’t cum.
This is why a good PE routine is your best bet. With the right workouts you will be able to not only have a bigger penis, you’ll have fuller erections and be able to delay ejaculating. It’s all in training your penis. If we don’t work it out, like we do the rest of our body, it will not function the way we want.