You can research until unsure, then do a design, works perfectly fine (with or without unassigning staff). Just keep in mind, research levels drop over time, its not rapid, but its steady. So reserch and then dev, you should be fine!
research is the max a part can be no matter how good head designer is - but yes you still want the assistant as this will help to actually design a part to the max level - this max level will prob be the potential of the part
When designing a new part (which you have to do for each new season at the moment) you need the best research level to get the best potential part. However when basing a design on a previous one, it uses the same research rating as it was when you made the original part. It is a waste of money and time to do research when doing a based on design
Yes, but keep in mind that based on is only working for in season dev. If you are doing a based on part for next season, you still need to research as it will be a brand new part non the less.
Based on is not working at all (it was working a few seasons ago, then happened a development overhaul, since then it is not working). So you have to research for every brand new part.
So for next season you research, and then design a brand new part.
EDIT: if you select based on for next season, it's still going to be a brand new part. So you still need to research before and the outcome is the same.
Nope, I have never tested this aspect as once I sent my designers then I leave them alone through the different phases. I would assume that if 20 was the fastest way to design and develop then it would also be the same for test bed.
