So far the 3rd reading has been delayed by two amendments - both of those amendments were proposed by independent senators appointed by Trudeau. Those amendments gave conservatives an opportunity to delay, and it would be stupid for them not to use such an opportunity. It's the 'job' of opposition to cause 'troubles' for the government (regardless of which party controls the government).
Each new amendment -> new debate -> each senator is allowed to speak again -> more delay from our (future citizens) perspective.
The only option (in my opinion) to fast-track the bill is to abandon all the amendments, and just focus on the bill itself. Let's be honest, Omidvar's amendment is a huge one, and it should have been a separate bill - it would have probably taken them another year to pass it, but I doubt that many people would be affected by it. Someone posted some revocation stats here a while ago - under 200 people faced citizenship revocation; compare this number to the number of people affected by C-24/C-6. I'm not saying that those people do not deserve an appeal process, but the amendment is not going to help them in any way because their cases are processed under the previous law.
Yes, I agree with you. Both immigration ministers (the former and latter) concurred that the bill was fine as it was; and the proposed amendments could be on a separate bill. I'm sure they know that the Cons would filibuster the heck out of this bill since its nemesis c-24 was passed within 3 days, which means the liberals had no real objection to that bill.