cl_interpolate 0
This isn't in the game anymore as it was removed with the most recent significant update. It has been replaced with cl_interp_ratio which should stay at 0 to match interp and rates by default.
cl_rate should be maxed out at 100,000 for servers that have ultra-rates. What your rate is set at really won't matter because 99% of the servers today have a maxrate set and will lower ones rate to the cap if they exceed it; same goes for tic rate.
The graphics changes are a good idea if you don't have a "great" system, but CS:S isn't that demanding so changing these really won't show much of a difference. Hitbox delay has a lot to do with client connection. You'll notice more of a difference messing with the network settings on the client side, but many times it's the server that causes that delay.
Try playing on a server with ultra-rates and high FPS; you'll notice a night and day difference with hitboxes without having to change anything.