Joe, according to your post, going to college in order to learn a trade can be a mitzvah (paragraph C). You just need to be sure not to be exposed to apikorsus in the classes you attend, which isn’t difficult.
Indeed, many Rabbonim attended college/university. The Novominsker zt”l attended Brooklyn College. R’ Hutner studied philosophy in University – philosophy being a subject which can contain apikorsus.
R’ Bender has said that his father, R’ Dovid Bender, went to college and actually became a CPA.
Regarding your story about R’ Segal zt”l, I have a relative who wanted to stop attending general studies, and learn the whole day. R’ Segal told him absolutely not, and at minimum you need a high school diploma in order to get a job.
At the end of the day, even if someone wants to live at the bare minimum level, working 3 hours per day is not enough to support a family. Not when you have tuitions to pay. For most people, working 8 hours per day isn’t enough to cover tuitions in full if you have more than 3 kids. It’s one thing to ask for a scholarship when you’re working full-time, but how can you ask for help when you don’t want to work a regular job?
Regular is a very vague term