given the limited information that has been reported (let's face it, most people here are running with the accused's version of events, more or less), there are a lot of possible, reasonable 'progressions'. . .what we know is that there was more involved than simply a sketch of a gun that led to his detainment.
in regards to 10a, based on the original news report by the waterloo record (not the subsequent opinion articles), it appears that he was informed at the school office of the charge:
"He said he went to the school Wednesday afternoon to pick up his three children. He was summoned to the principal’s office where three police officers were waiting. They said he was being charged with possession of a firearm."
in regards to 10b, again based on the news report, he had legal representation at the police station, where he spoke to a lawyer, and while he claims many things, he does not suggest he was denied the right to a lawyer, or access to representation. we do not have full details of what transpired in the principal's office, so we cannot assume that he responded to questions without a lawyer present. in fact, he probably refused to answer questions, asked for a lawyer, and then was taken into custody. by his own admission he had two somewhat recent convictions, i would guess that he knew enough to ask for a lawyer and not to submit to questioning by police officers without one.
in regards to section 8, i think his reasonable expectation of privacy was vitiated when according to the waterloo record, he consented to have his home searched, when he knew he was not obligated to.
as i have written before, imho, there are not enough details to definitively suggest he was treated unfairly.