I do have my reservations about using the Richview Corridor for the LRT. It may be better to use a ROW and sell off the lands north of the line to developers. This would help to create a far more walkable community along the LRT route. The lack of lights on Eglinton West hopefully means that the LRT wouldn't be any slower than if it used Richview. However your concerns about the bus terminals are fully valid. Using Richview would definitely mitigate those concerns as well as better future proof the line.
Anyways if we do utilize the Richview Corridor elevating or trenching along the whole route will probably be too expensive given how few passengers we're expecting east of Jane.
On the 3 km stretch between Martin Grove and Royal York I'd prefer for the LRT to run north of Eglinton along the Richview Corridor. This would run at grade in a fully protected corridor, with stations at Martin Grove, Kipling, Islington and Royal York. At those streets, the LRT would dip just below grade in a trench where the LRT station will be built. At the other end of the station the line would rise to at grade again. This would allow for a proper bus terminal setup. With at least 1 km between each station we should have more than enough room to transition from below grade to at grade and back below again. Drivers on Russell Road, Wincott Drive and Widdicombe Hill Boulevard would have to cross the LRT tracks through a level crossing, where the LRT would have full signal priority. I'm not expecting these level crossing to be detrimental to operations since they're all small residential streets. The cost of this would hopefully be comparable to the cost of reconfiguring Eglinton West with a ROW.
Just east of Royal York we come into contact with some buildings, meaning that we can't build tracks on the north side of Eglinton. At Royal York Station (trenched) there would be an underground portal at the east side of the station that would run under the westbound lanes of Eglinton so that the line could transition to a centre ROW on Eglinton West. The line would continue along the ROW until just west of Scarlett road, where there'd be a portal running under the westbound lanes to a trenched station on the north side of Eglinton at Scarlett. This is essentially the same setup I described for Royal York station, just with the portal on the west side of the station rather than the east. Even through this section is in a ROW, the LRT would be fully protected from traffic as there are no street crossings between Royal York and Scarlett.
The LRT continues at grade on the at grade north side of Eglinton until Jane, where it will become elevated to connect to the planned elevated western terminus of the ECLRT at Weston Road. An elevated station would be built at Jane.
I'd expect the stations to be barebones so that costs can be kept low. They'd be unmanned, have a simple enclosed platform, (eg platforms at any of our at-grade subway stations) and have escalators/elevators. What I describe is probably the cheapest way to go about using Richview. It would very likely cost about the same as the ROW as long as we don't go crazy with station design.