I am building a small application for a friend and they'd like to be able to use Excel as the front end. (the UI will basically be userforms in Excel). They have a bunch of data in Excel that they would like to be able to query but I do not want to use excel as a database as I don't think it is fit for that purpose and am considering using Access. [BTW, I know Access has its shortcomings but there is zero budget available and Access already on friend's PC]

To summarise, I am considering dumping a bunch of data into Access and then using Excel as a front end to query the database and display results in a userform style environment.

Questions:

1. How easy is it to link to Access from Excel using ADO / DAO? Is it quite limited in terms of functionality or can I get creative?
2. Do I pay a performance penalty (vs.using forms in Access as the UI)?
3. Assuming that the database will always be updated using ADO / DAO commands from within Excel VBA, does that mean I can have multiple Excel users using that one single Access database and not run into any concurrency issues etc.?
4. Any other things I should be aware of?

I have strong Excel VBA skills and think I can overcome Access VBA quite quickly but never really done Excel / Access link before. I could shoehorn the data into Excel and use as a quasi-database but that just seems more pain than it is worth (and not a robust long term solution)

Any advice appreciated.

Alex