So the SMN has extra summon damage, a 10 point increase. This is minor in my opinion.
Summon 3, which is, as I have read, less useful than Summon 1 (after the upgrade).
Fester, an extremely powerful spell with a power of 300.
Tri-disaster, fairly useless in most places, although of course is useful.
Spur, a huge 40% increase in damage to summon.
Enkindle, of course powerful, but with a 5 minute CD, it seems fairly useless except saved for when you require the extra burst.

Question 2: Is the power of the SMN really so closely tied to just spamming Fester? I know there is more power there, but it seems a little simple, other than when you want to spread the infection, and need mana or HP, is this really what the SMN does to deal damage, just uses it as much as possible? (of course it requires Aetherflow).