I have questions about how to use the new directory structures we now have under Windows 7 and Vista. Five main questions:

1. What are the pitfalls of just making up my own directory under c:\, such as c:\mysoftware\ and reading/writing stuff from there? Both from the perspective of a software installer creating and using that folder, and from an end user who creates and uses it. What problems might this cause on a multiple-user machine? I do it this way for tons of little command-line utilities and shareware tools I like to use, and never seem to have a problem with it.

2. A few software programs I have put all their data in a folder at \Users\[user]\ instead of under \Users\[user]\AppData\Local or Roaming. Is this bad form? For instance, my Kindle Viewer puts data in \Users\[user]\.kindle.

3. Some programs in those Local and Roaming directories start with a dot (for example, .minecraft and .ffmpeg), while others don't use this (Adobe, TightVNC, etc). Is one way correct, and not the other way?

4. Do applications have to be installed and executed out of the Program Files hierarchy, or is there leeway for executables in other directories elsewhere? Unless I'm rusty on this, Program Files requires privilege escalation, and I've always heard users shouldn't need Administrator privileges to be running their computers (maybe an exception with software installs is implied?)

5. I'd like a crash course on good practices for where installer programs should be placing their content on W7/Vista systems. A good, succinct reference somewhere is fine... this seems to be hard for me to Google without finding a ton of MCSE and sysadmin type material.

Many thanks in advance!