Far too much to read today.
Having your own site does require people to search for you via a web search engine. But that is not big deal for people who are looking to add to your family if you provide good meta data for the search engine. Meta data is what puts your site on the first page of the result list.
For the most part Ancestry and RootsWeb try to lock you into their site and not let you go. This is one of the downside to them not supporting GEDCOM correctly, they make it hard for people to get out. However if you can live with these restrictions, limitations and "gotch-as" they are pretty much the only games in town.
I always, regardless of the software used, tell people at the genealogy center where I volunteer, pick a program (one program) and use it. Learn as much as you can about how to make it work, find out all the workarounds that make it do what you want within the bounds of the software you can from other users. Every program has limitations and requires work-arounds, even the program I use does not have every feature I would like to use, but it gives me the best control over every other program I have used.
DO NOT EXPECT to be able to transfer data between programs without loss, so pick one and tell everyone you can to use that environment.
Obviously I am a little sour on ACOM because they are well noted by users to have issues with the way they store and what they store on their system. The data kept is not very robust and not easy to offload to other programs, but they have a direct connection to the sources kept on ACOM and that is very helpful to genealogist that would rather have the software do the recording rather than being their own librarian.
I'll continue to read your message above to see what other questions you have. I'll be happy to answer them as time permits. I don't use either ACOM or RootsWeb at this time, I tried them but found them lacking in reports, following librarian practices, open structure and interface, GEDCOM standard adherence, and other stuff that I could not live without.