Sam Spade writes:

You did it wrong about every way possible.

Okay. Please describe the right way ... and provide references.

First, by what authority did you descend 700 feet flow the MEA for V-187
simply because you were within 25 miles of AST? The MEA is 5,000 all
the way to AST VOR. That is basic chart reading.

The plate gives the MSA within a 25-nm radius. Once I was within the 25-nm
radius, I could safely descend to the MSA, and I did so, because it
facilitated entering the approach.

Then, when you turn around at about 12 miles and headed north you
departed protected airspace.

I'm not sure what you mean by protected airspace. Once I was clear of the
Seattle Class B, the rest of the flight was conducted entirely in Class E
airspace, right up to landing.

The 19 DME arc is available only to non-radar arrivals on on V-27
(R-328) from the northwest or V-27 (R-166) from the south. For any
other arrival the approach begins at AST via the feeder route to KARPEN,
then the procedure turn.

Okay. How do you know this? Explain where and how it is documented on the
plate, or where it is documented elsewhere, so that I can look it up.