Although I am in the UK, I buy a lot of cameras and related equipment from Japan. I have never had any sort of problem but I suggest that you only buy what is described as 'Mint' or 'Near Mint'. Things described as 'Excellent' may not be what we consider excellent. I find the sellers very honest and prompt senders

That Tokina is very good indeed!

I use a Tokina 100mm f2.8 prod macro which is more than adequate for my needs. Use with a tripod and you should be delighted with superb results.

I have bought lenses from them and found their descriptions very accurate and they were good to buy from

I use a lot of film and have no problem sourcing it but I am in the UK and I suspect you are not. NTPhotoworks.com are located in S.E.England in Folkestone in case that is any use to you. They will probably send film to you but carriage and import duty may make that prohibitively expensive. They also have a great range of processing option.

Free air still available here at a filling station near me.

I have had this new film on pre-order for several months and understand delivery is now not far off. As for a cheap film camera you can pick up great condition a Nikon FM for a give away price and these are, as you probably know, totally manual. Another seriously good camera is the Nikon F90X (not sure about the US designation. These were marketed as just sub-pro cameras at the time and they have auto focus and lots of other stuff not on the FM. 50mmD lenses are also excellent and at very reasonable prices

In my case, I listed quite a few but only ones that I actually use regularly

Nikon F2, FM, Bronica ETRS, Mamiya RB67 ProS, Leica llF, Zeiss Ikon Nettar, Intrepid 5x4, Intrepid 10x8

You don't 'hop on, hop off' on taxis. They take you where you want to go and relieve you of lots of cash. You are clearly referring to the vaporetti. It is no use giving advice that uses the incorrect terms.

The 'water taxi' is not cheap, far from it. I suspect that what you refer to is a vaporetto, the equivalent of a bus. It is very important to use the correct terms when giving advice or there could be a nasty, expensive, surprise.

I know Venice very well although I stay on the mainland with friends. Staying in Venice itself can be very expensive so you might want to investigate hotels in Marghera or Mestre both of which are at the other end of the ponte della Liberta which connects Venice to the mainland. Both of these are very well connected with regular bus and tram services. I usually take several cameras to cope with different situations that I know I will meet. In fact, the one I use most is probably a tiny Nikon V1 followed by Fuji X-Pro1 or Nikon D7000. I haven't been to the Carnivale but I know that it becomes insanely crowded so minimum equipment is probably sensible.

I have bought many used lenses and camera bodis from vendors in Japan and all of them are exactly as descibed in their advertisements on Ebay and all excellent.

No need to toss it yet. Depending on the type of film it will give results of some sort - maybe interesting colour shifts. Photography isn't necessarily about perfect results (whatever that means) but getting some satifying and interesting results. As others have said, use a roll on somethingnot especially important to you and see how it turns out.

Look in a mirror before you go out to remind yourself what you look like then get on with your day.