@julian well I was looking for a help right now. Already paid for server and domain. And looking for Adsense so that I can earn what I've invested right now. Thanks for contacting though but I am not looking for paid service right now.
Found the solution, importing too much topics in a single category hangs the nodebb, import some data than move it to some temporary category. Thasn import remaining data, meanwhile delete mongodb import Garbaze in using these mongo commands
But keep in mind this will also delete the history of import will result in duplicate categories get imported or the posts, to prevent this keep writing post ids and category ids which you imported and delete them from the old database.
Thank you for the links. As the "how to import" question will be important for many users I'd highly suggest to add this information into the docs and wiki.
Did no one (including the "paid support") wrote this importer before?
If not I'd even suggest the "paid support" have at least a thought if an official import option for Allura exports would help nodeBB in general to grow - especially now as SourceForge (which uses Allura and has the same export) looses users which look for alternatives which are able to import the old forum data with as less as possible effort.
Basically import isn't ready for v0.8.2 just yet but akhoury is working on it. Personally I'll wait for an updated import rather than downgrade->import->upgrade given my trouble with plugins and v0.7.x from npm.