Re: Decision tree?
There's logic in it, but it's a lot more work and there are potential problems, for example:
"Do you use rare functions of Microsoft Excel which won't work well in LibreOffice Calc?"
Some users select yes because they use really complicated features of Excel like the formulas and that box that makes graphs.
Some users select no because LibreOffice looks like it's got a lot of features, so it will probably work.
Most users select "I have no idea" because they've never tested anything in LibreOffice.
It's hard to ask sufficient questions to give a good answer without running the risk of confusing users, possibly causing them to just give up. In some respects, it might be more reliable to simply give them some version that's likely to work and letting them see if it can do what they want, and if I had to recommend something for people who have no support and insufficient knowledge to figure it out for themselves, I might propose that method*. The problem is that it's not easy to coach them through installing it in such a way that, if it doesn't do what they want, they can go back to Windows safely, because it's very easy to break dual booting if you don't know what you're doing during installation and that will just mean a lot of people angry about how Linux broke their computer.
* I have helped people by giving them equipment which I created out of discarded computers and parts. I didn't have Windows license keys just sitting around, so they came with Linux, usually just the latest Ubuntu LTS, and I told users I'd help install Windows if they bought or already had a license and asked for that**. Quite a few of them were able to find the applications they needed. I'm not sure I ever found someone who didn't react with some uncertainty when faced with it, but since many of them just needed a web browser and word processor, Ubuntu was often fine. At least, if it wasn't fine, they would have a specific thing they had tried and didn't work which I could review which was more reliable than asking them beforehand and hoping they gave enough information to predict it.
** I wasn't trying to promote Linux there. Whatever the user wanted and I could provide, I did. I did try to avoid spending a lot of time personally teaching them how to use the machine, though, because that is a nearly infinite time sink. I really respect those who have the time to do that more consistently.