I am not going to quote all of the other quotes, so I just hit this one. I admit I am on a thin ice of knowledge of sponsorship in F1. First, I will say do you have a link to constructor prize money? I have always thought that was a secret. Second, I just can't see sponsors being that loyal to teams over drivers. In the past, a lot of drivers have brought their own sponsors. I know it is a complex arrangement, but does any sponsor really care to put in its advertisements a championship team over a champ driver? In the states especially in Nascar, the sponsor is more closely associated with the driver than the team.
As for Mercedes and Lotus, Tack pretty much explained it. I really don't find Lotus that complicated at all. It was Renault and then they sold out to Genii(?). I am sure it was mostly because of the Flavio debacle. (Speaking of, whatever happened to Piquet Jr?)
Most of the F1 racing industry is in England, just like Nascar's industry is in Charlotte and Indys is Indy (does anyone really care about that series anymore?). Trying to build a car outside of these hotbeds is much more difficult and expensive.