My two cents, but I am sure there are plenty more folks out there with much more experience than I...
Venting, I have always vented until foam stops running out, typically I will use a venting tool, but if I do not have one I will use the hard spile to make the hole and then put a cloth over it while venting (that way it does not go everywhere too badly.) Once it is done foaming, if it foams at all, I will put the soft spile into the bung. When I am done pouring for the day I will hard spile it.
As to keeping it cool, gel packs, ice packs, or those ice blankets made of those small squares where you can remove a square to put it over the bung work really well.