Testicles are supposed to be cooler than the rest of your body, that's why they're in a sac hanging outside your body. Not sure if this seems to be a new symptom for you, or why you're more aware of it now than before.
If the quality of your erections isn't as good as it used to be, it can be an issue of your general health, nutrition, fitness, weight, etc., not a specifically urological issue. You might need a general check up with lab tests to make sure.View Thread
What you describe is not priapism and probably has nothing to do with your surgery. Its probably totally normal, and a sign that you're healthy.
Healthy men have erections off and on all night, and it might seem to be prolonged because it's hard every time you wake up. The dreaded "4-hour erection" that you hear about on TV ads is a way the pharmaceutical companies cover their rear ends from potential law suits. There are however some prescribed medications and medical conditions (notably, sickle cell) associated with prolonged erections. You should be aware of side effects of any medication that you're taking.View Thread