The rotes wouldn't change except for the last one, which assumes you're in "demonic co-pilot" mode.
You have +5 conviction and +5 discipline
Necromancy control bonus is +1 from Kemmler, +2 from focus item, +1 from specialization, or +4
Spirit offensive Power bonus is +1 from specialization, +2 from focus item
Spirit defensive Power bonus is +1 from specialization
So for control shifts you have 5+4 as long as you're using necromancy influenced spirit attacks
For power shifts you have 5+3 as long as you're using offensive spirit power.
So your rotes can be 9 shifts of control if they're necromatic and offensive and 8 shifts of power as long as they're tied to the focus item. So the rotes are all fine.
As for summoning undead on the fly, you'll have
necromancy control +1, +1, +2, +2
necromancy complexity +1, +2
so you'll have a base control of 11 and a base power of 8. According to the book summoning and binding should take between 16 and 24 shifts of power. So yes. For one or two fate points and probably a 4+ mental stress attack on yourself and a little fallout you'll be able to summon undead on the fly.