tinanam0102“Could the preposition be taken off out of the text and still preserve it's its original meaning in the following sentences? ”
Yes. More or less. The differences are slight.
1. It's a matter of stalling the vote itself vs. stalling (doing whatever would create a delay) with regard to voting.
2. It's a matter of delivering the goods (performing well) vs. delivering (performing well) with regard to what she had to perform.
3. "stall off" =~ "stall", so that you could also have:
The opposition parties tried to stall off the vote.
or
The opposition parties tried to stall the vote off.
or
The opposition parties tried to stall off on the vote.
"stall on" is not a phrasal verb. "stall off" is a phrasal verb.
CJ