The scorestreak thing I think is just a Gametype issue. I've gotten 3 steath choppers in one match of kill confirmed back to back because I played the objective (have proof also). Games like TDM make it much more difficult to attain high SS because of the lack of potential points. All you have are kills and assists for the most part which aren' that consistent or high. The big issue imo is lap comp because it can make or break any match.
It would be nice to hear footsteps again, but I doubt it will happen. This game has such great sounds, the footsteps are so dynamic based on what you are walking on.. I feel like they want to keep it more realistic.