As for the first, you don't want to be in an environment that values credentials so strictly, imho - it poisons the air. There is always a chance they would then say "we only hire CS from Stanford/MIT" - sometimes stuff like this is just a polite way of saying "we don't think you can cut it".

> I imagine I'll learn everything about security and algorithms

Algos yeah, plenty - and I agree it's where universities really make a difference (I'm weak there too, and part of the reason for dropping out, and more recently changing career, was that I'm not really interested in that part of the job).

Security... eh. It really depends on the program.