I am only familiar with surveymonkey and google docs.
I have two purposes in mind:
1> Gathering basic information about what people might like to have when they attend an event (actually I am working with several orgs to develop events)
2> Gathering numeric information and then having the survey return a result, such as a dollar amount.
I've been pretty happy with Survey Monkey. If you want to do some deeper analysis on the backend, a simple export to Excel allows you to run pivot tables, and all sorts of other functions. Is there some specific function that you are looking for that Survey Monkey can't handle?
I'm not sure I understand your second point well enough to comment.
As to the second question, I am thinking that I may have to develop an HTML input form, or maybe a .php form, so that people that land on my site can run some simple business calculations and they get the answer back. And I get their contact info as a list building tool.
Gotcha....no immediate solution suggestion for you.....If you end up having to build something you might want to consider building a widget, so the applet could be distributed (embedded) to other sites as well.
Grrrreeeaaattttt..... I know tooooo much about tech as it is. I spent maybe 15 hours this weekend updating the look and feel of 2 of my 3 blogs this weekend. Code junkie I am! But I like the results.