Ignition Effect Priority in Old Yu-Gi-Oh!
Correct.

Going further, only the monster that was summoned would be allowed to activate its ignition effect (which answers 7 and 8).

Also correct due to ignition effects being treated as having spell speed 1.

Incorrect, only the summoned monster would be allowed to activate its ignition effect with ignition effect priority.

Correct.

Correct, however I also believe that it cannot be a summon during the resolution of a chain (by card effect such as polymerization), for a special summon it would have to be by summoning condition.

Answered in 2.

Answered in 2.

No, answered in 6.

No, answered in 2 as the summoned monster would be in the opponents control.

No, as you cannot summon monsters via summoning condition on your opponents turn.