txviking

I'm planning to go on a Panama Canal cruise sometime next year. I searched the forum and didn't find a whole lot of information on these, so looking for some advice. My questions are somewhat generic, but I would love to hear about the experiences of people who have done this trip.

1) I plan to go by myself on this particular trip. Which cruise lines will have the best options for single occupancy cabins (or the lowest premium for a single traveler in a double-occupancy cabin?) Prefer outside view or balcony.

2) I have asthma. It seems nobody does completely non-smoking ships anymore, but several cruise lines at least prohibit smoking in cabins, on balconies and in most public areas. Who is best in this regard, and who should I avoid?

3) To me, the two-week cruise seems to be the ideal length. Any reasons not to?

4) Any recommendations for shore excursions and things to do on this trip, either via the cruise lines or independently?