Migration to BW 7.4 on HANA from 7.3 and 7.0

All,

     We are migrating one BW 7.0 system and another BW 7.3 system to 7.4 on HANA. Since this happens to be the first time, we are looking for compatability/version adaptability purely with respect to BW objects.

1. What precautions to be considered w.r.t BW object migration from 7.0/7.3 to 7.4 on HANA?
   1. Like for Ex: Transformations with routines will be deactivated when moved to 7.4 as there is a new pop-up through which the fields needs to selected. True?
2. Can 7.0 BW objects be moved directly to 7.4 ?
3. Please help us with your Migration project experience or knowledge

Thanks & Regards,

Sankameshwar