Tinsley and Nazr are essentially a salary wash, so it comes down to Foster + third player for Felton from Indiana's perspective. You've got to think that that's a talent upgrade, but how many PGs does Indiana need on its roster? (Ford and Jack are there now). If the third player is Rush or Graham, I'd do it from Indiana's perspective. If it's Daniels, I wouldn't, just due to roster balance.
As for Charlotte, I'm not sure why they're in such a rush to get rid of Felton. Foster is a decent player, but I probably wouldn't do the deal from their perspective, even with Daniels.