Good, constructive comments. I meant to address the electrification issue, but didn’t get to it. I had suspected that wiring the cross streets would be a good medium term capital project, but hadn’t considered the issue of crossing the tracks. So you’re right, the circulators stick us with diesels. Another drawback, I guess.

I would dispute your statement that the 39 and 48 would be best. The 39 is half-hour service, the 48 15-minute. On Beacon and Rainier you have at least one, and often two, circulators going by every 15 minutes in each direction.

It’s true that some trips are going to require more transfers — I believe that’s inevitable when there’s no route that exactly matches LINK, if you’re going to eliminate routes at all. For instance, there isn’t any direct way to get from MLK to the I-90 freeway station if the 42 goes away, which is probably going to happen, and affects me personally.

To address the specific example that you raise (RB to Little Saigon), if they’re close enough to RB station it’s still a 2-seat ride, and much faster to boot. The idea here is that LR gives you enough time savings over the bus that for really long-haul trips up Rainier and Beacon the circulator transfer (or a bit of walking) probably washes out in terms of time. God knows the 7 takes forever to get all the way uptown.

The loop concept seems good to me and might allow better bus service to Capitol Hill by getting the 7 and 9 away from busier streets and difficult intersections.

The loop routes in either concept would have to be diesel buses for the foreseeable future: the lateral connections of the loops have no overhead trolley wire; the extensions Metro is constructing in time for Link next year do not cross Link light rail. I’ve heard there are issues with the fact that the Link overhead catenary wires carry 1500 volts while the trolleybus wire is 700 volts (1500 volts is a typical for light rail); It would be an exciting fireworks display until one of the systems faults.
In Concept #1, the 36 routing shown would have to be a diesel bus since there will be no wire south of Othello Street. The route 9, on the other hand, could become a trolley bus, unless you want it to skip stops north of Mt. Baker Station. In which case, all buses would need to be diesel south of Mt. Baker Station (since the #7 would be in the way at most stops).
Concept #2′s elimination of the 9 and 7 south of Mt. Baker Station and the 36 south of Beacon Hill Station Mt. Baker and Beacon Hill Link stations respectively would mean a complete elimination of electric transit service south of these Link stations.
Traveling up and down Rainier Avenue in Concept #2 appears to become rather difficult. A trip from Rainier Beach to Little Saigon would require two transfers (either on Rainier or using Link), for something today requires no transfers. If headways are optimized for transfers to rail, then transfers on Beacon Avenue S and Rainier Avenue S would likely be suboptimal.
I believe (correct me if I’m wrong) will typically be 7.5 minutes for most of the day to S. Henderson Street Station (half of trains would turn back). Would 15-minute headways on buses have sufficient capacity to effectively “feed” Link?
With the loops, where would bus operators layover? This would be important to identify early on, since some part of the loop would be disrupted by waits of 10-15 minutes; longer than most people will want to sit on a bus that’s not moving. Light rail stations would probably be the easiest to have layover, but it disrupts the concept of the circulators providing intra-valley travel.
It looks like the best bus service in the valley would be the 39 and 48. MLK consequently has both really good rail and good bus service while Beacon Avenue and Rainier see a significant reduction from today’s service levels (10 minutes) plus more diesel buses than currently.
Concepts that reduce the number of trolley buses in operation will likely have a negative impact on Metro’s fleet constraint, since the constraint is primarily in the diesel fleet. Trolley buses (and particularly the 60 foot trolley buses on the 7) are far less fungible/transferable than diesel buses.

#2 is a nice trick, and saves quite a few buses to do almost the same job. It looks like it should give the same frequency of service as currently exists, so it may be a good short term option since KC can use all the buses they can find right now.