1. I agree that deleting a question can be improved, e.g. there could be a notice "There are X conditions linked to this question. By deleting the question, the conditions will be deleted as well".
From a coding point of view it should be possible to delete the question PLUS condition(s).
You can
add this as a feature request at our feature tracker . Please describe your idea as detailed as possible and try to outline a suitable solution/implementation as well.
Problems might arise if you use chained conditions. This will be hard to track and we'd probably have to leave it to the user to check for such cases.
2. as an alternative to delete all questions manually, copy the current survey and check the "Reset conditions?" option. You can then easily splitt up the copy.
Another alternative might be to export/import groups between the different surveys.