Hi,
1. I’m afraid no, connection to the local server is still required. Without that the search requests will not work.
2. You can’t unfortunately. The keyword suggestion queries are kept as simple as possible, as it is executed after the search, and at that point a decent amount of time and resource is probably used up. The only way you could do that is by making direct changes to the query files, which I do not recommend.
Although I think you have a valid point here about the number of items per taxonomy, as currently the suggestion algorithm indeed selects the most similar words from each source, and once it gets all, it is done. Maybe I can improve this in the upcoming release, to try to take keywords from all taxonomy sources first, and then make a selection for the most similar ones. That would make sense.