> Can i embed the main trackers page: tiki-list_trackers.php inside of a WIKI page?
Yes, using SNARF plugin (search the doc.tw.o site or this tw.o for more information about it)
> Can i embed html inside of a WIKI page?
Yes, in Wiki pages (using use html perm and option in a wiki page while edtting it)
Ourtside of wiki, but within Tiki, check "html pages", "integrator" and "Featured Links".
> What is the difference between trackers and the user tasks ? It seems like the user tasks are a less flexible version of a tracker ?
Sort of. For tasks, users tasks is already done, but you could make it your own way through trackers, which also allow making any other set of forms, database, and queries to that databse of items through TRACKER plugin, TRACKERLIST plugin, TRACKERFILTER plugin, etc.
Welcome on board, ak...