After many trials to run HSDK on normal kernel & Inception, I am 95% sure that hsdk installation bricks (next reboot it keep rebooting) the MeeGo Harmattan OS when open mode kernel is not used. A firmware reflash fixes this problem (but all extra softwares are deleted).

Anyway, using HSDK I've created a "Harmattan SDK final" image and it works well with qchroot (from HarmChom), without HSDK.

(Update) I've tested HSDK 0.0.3 and looking inside the .deb, there are some system file changes, maybe they are the reason of boot loop when using Inception (and without open mode kernel) on my N9.
Previous versions of HSDK don't have system file changes, maybe they can be used with Inception & without open mode kernel. But I can't risk to test it now as my N9 is well configured and being used a lot.

(2nd update) HSDK 0.0.1 works 100% ok for Inception users (without open mode kernel), see post #13.