" LS4 will have a new HTML-Editor." : yes, we will update to CK5
"LS4 will offer the Twig-Templateengine for E-Mails" : yes. If we have time in 4.0, else in 4.x, knowing that we'll keep the current keywords also (they will be removed in LS 5)
" LS4 will have a normalized datastructure (no more table limit issues)": for languages, yes. For survey itself, no.
" LS4 will offer real objects (ORM access style) instead of the aSurveyInfo.": for the sake of survey theme retrocompatibility, aSurveyInfo will be here, but yes, we'll add the access to the main data model objects
" LS4 will have a RBAC permission system." : still not. Unless we realize it can be done in a very short amount of time.
LS4 WILL include a new component system ( add Menu + full page feature in the backend): that's one the main goal of it for now.
For the shop: see with olle