Unfortunately, we don’t have demo software. But, you can get a license for 1 month to test the software.
Yes, you can. You can get a licence even for 1 month for a pretty low price and see if the software meets your expectations.
The licence is issued per computer. Following your installation, you need to get contact us on firstname.lastname@example.org and ask for your licence.
Nope. If WinTess warns you that there is a new version on the server, you can safely install in on top of the old one. Your license will be preserved.