The last two have been discussed before, but for question b) IMO, increasing it doesn't really add or take away anything. It would keep up with inflation, but losing a maximum of $1,250 in a round still creates a risk. If it were to ever go up, maybe make it $500, but I'm cool with it either way.
As for c) some of the shopping segments and descriptions took several minutes, which in turn takes away from gameplay.
A while ago, I came up with the idea of a shopping round, where you have to land on a space worth say, $1,000 per letter, which then goes onto a "gift card" of sorts. Solve the puzzle, and you use the gift card to "shop". No On Account or anything, just a small incentive for solving a puzzle, while going old-school. It wouldn't even have to be done everyday. There's more kinks to iron out with the idea, but I get off work in 8 minutes. ;-)