None of this is written in stone. If there were absolutes here, we would all have 12 inch dicks.
There is a wide range of responses to PE, from awesome to none at all. So with that in mind, I will try and give you some sensible answers.
1) If you got good initial gains, and RETAINED THEM….chances are you already got your “newbie gains” and may not gain as rapidly as before. On the other hand, its been so long since you last PE’d, you many just get a whole new set of “newbie gains”. I recommend you do the same routine you did before and see if you get the same results. A long layoff, in general, tends to IMPROVE your chances of gains. We call it a “deconditioning break” and it is almost always a real good thing.
2) Did you do warm ups before? If you didn’t before and got gains, I say you can probably do without them again.
In general, warm ups tend to be beneficial for most guys…for a number of reasons. However, there are plenty of guys that did just fine without them. Once again, I would suggest you repeat what worked for you before…and stay with it until it stops working. At that point you could try and increase the time or take a couple weeks off then restart the program.
Good luck.