1. I feel entirely the opposite way about the appeal of an MIT-style license that includes a patent grant. It's not primarily about making the author feel comfortable — as the author probably doesn't have patents, and doesn't intend to. It's about giving the user of the software confidence. Because the user has no idea what patents the author may or may not hold. At this moment, this is playing out to dramatic effect in Facebook's open source projects — you can see an example here: https://github.com/facebook/graphql/issues/351
Being able to give users of my software fuller confidence under the Lil License also makes me more interested in using it as an author. It's a virtuous cycle.
2. I'm afraid I still don't quite see the issue you're describing here. If I'm following correctly, the hypothetical case is a contributor who writes a bit of code that exercises a patent that she has a license to, but not permission to sublicense, and then wants to submit that code to an LIL-licensed project. If she's not allowed to sublicense, then she can't contribute that code. She wouldn't be able to contribute it to an Apache project either.
3. It might be. I think that its width is more suitable for most open source projects than the narrower Apache and MPL, but that's something that would make for a good discussion. I'll open a ticket.
4. Again, we're talking past each other a bit. This isn't really trying to appeal to the Facebooks of the world — it's trying to appeal to us regular folk. That I might be able to convince people without patents to use the license is not irrelevant, it's exactly the point. Those people are the target audience. From a user's point of view, the patent grant is still important — because I never know for certain when an author may or may not hold a patent on the code.
5. If I grant you usage rights to a patent, I grant you a license to make, use, sell, import and otherwise transfer implementations of the invention described in that patent. If you think we need to spell out all of those words explicitly, perhaps throwing in "have made" and "offer to sell" as well, feel free to open a ticket and we'll talk about it further.