This is very promising, I was in the process of writing down my own requirements and it seems most things are already covered, although it's not clear from your post if we can have per-wiki stats as well as per-job stats.

Since we cannot count jobs in queue properly anymore, we would like to have the following metrics to be available/collected:
 * Processing lag (defined as the Xth percentile of age of rootJobTimestamps in the last minute, in the current model for the jobqueue), for each job type and for each wiki.
 * Rates of job insertion, again for each job type on each wiki, and corresponding totals
 * Rate of job processing, as above
 * Rate of job failures, as above
 * Rate of jobs dropped because of deduplication, as above
 * Ops and services will have to come up with sensible alerts to set up based on those metrics.
 * Every changeprop instance should expose an endpoint for health-checking (this is distinct from the global metrics above)

There is a second part to my list of "requirements", but I'll post those to a separate ticket.