With respect to #1, another possibility is, instead of having project builders, just committing the generated sources, as Ed Willink suggested in
Bug 479634. But before making a decision, I sent an e-mail to IncQuery to check what was their original objection, and what approach would they prefer.
With respect to #2, I'll push a gerrit to fix it. We would still have to build the Xtext artifacts, and that should be done with a builder. I'll open a bug for it.
You are right that you don't need codegen to create models, so it's OK for a development environment. By the way, you still have to create a run/configuration manually, right?
As for the name of the checked out branch, I'm not sure. I thought I chose neon on all those, but I just started testing it again, and Oomph seemed to remember the last settings, and showed that I had selected Neon for all except for the "Releng/Oomph" component. This time I tried making sure I set all of them to neon, and it worked as expected. So, in the case where you choose different branches for different components is the expected behaviour to choose the last one? Or something else? Seems a bit confusing, if you select different branches. Makes me wonder why, if you are selecting components only from one git repo, should you be allowed to enter different branches for different components.
As for the name of the cloned git repo, my default is "${git.container.root/}${@id.remoteURI|gitRepository/}${@id.checkoutBranch}" so the name of the folder is as expected. I don't have a problem with that, but what I find confusing is how it's shown by EGit (so it's probably an EGit issue rather than an Oomph issue): it seems to show the name of the repo as the last segment in the path. It's not a big deal.