Yes. The issue is the word "swap" has several meanings. When you say "swap allocated", you talk about virtual memory but when you say "swap used", that might still be virtual memory (swap -s) or on disk swap (swap -l).
Not that much. Generally, most of the paging activity won't be related to the on-disk swap area but just regular files read/write operations. Therefore, hi page-in/page-out counters do not imply there is a shortage in RAM, just some active disk I/Os. As I wrote, the relevant statistic about RAM shortage is the scan rate (sr).
Not an easy task, and depending on the method used, reading what is there would have the side effect to page it in, i.e. to put it back into RAM.
You can have detailed information about a process memory usage with the pmap -xs command.
The blocks related to swap are tagged "[anon]" for anonymous. That means the pages have no file back-end. The RSS column tells the number of pages that are currently in RAM while the KBytes column gives the size of the block.
Knowing these addresses, you can use the kernel modular debugger (mdb -k)to retrieve the mapping between virtual addresses returned by pmap and the corresponding physical addresses.
Yes, and I have already observed such puzzling at first sight situations in real life systems.