Mark,
Blood and clots after a TURBT happens often. Not everybody, but a good number. As Pat already said, it would be better to get the 2nd TURBT at MSK. Once bladder cancer is confirmed, it is best to get directly to the top docs at the top places (and that's what you are doing).
Good to hear that the slides are already at MSK so all should be ready for your appointment. It would be a good idea to get all of your uro's records sent as well. Most are happy to fax them over to the 2nd opinion doc, but I requested copies of all of mine because I started my own log of everything (Dr. Notes, surgical notes, CT scans, x-rays, IVPs, basically every test/BCG treatment, mitomycin treatment, cystoscopic exam, etc.).
I had hard copies, scanned copies, and CDs with all the images. I went to a 2nd and 3rd opinion but if you're going to MSK, then I don't think a 3rd opinion would be necessary.
Best of luck on your follow up at MSK. Hope the diagnosis stays T0 after reTURB and reviews. Even so, you want to keep all of your records because bladder cancer has a high recurrence rate and it is good to track everything. Write down your questions and write down the answers that the doctors give you and keep a log.
Mike