These are all great thoughts. Here are some of my own:
1) There is literally zero reason to extend a streetcar along 200 South all the way to the University. If you're trying to get to the university from Central Station, you would not want a system that is programmed to make many stops along the way for the sake of 'encouraging development.' No, you'd want an express bus that goes straight there with no or minimal stops, like the 2X does currently. The University is a big enough trip generator to warrant this type of service, so 'encouraging development' with a streetcar is not needed.
2) Without a firm eastern terminus, the streetcar's usefulness diminishes for each block it extends eastward. The area between Central Station and Main Street are pretty good for a streetcar, but that's less than a mile in distance and that is a service already offered by TRAX two blocks to the north.
3) TRAX will have its own lines on both South Temple and 4th South by the time the streetcar gets built, duplicating its service two blocks away on both sides. It will be surrounded and have very low utility. Basically, if you're in the range between 100 South and 300 South, you get your own streetcar. Otherwise TRAX is closer and more convenient.
4) A streetcar can connect 200 South only to itself and Central Station, whereas a BRT line (or better, network) can connect 200 South to itself, Central Station, and all the rest of the Salt Lake Valley. If a map such as Liberty Wellsian's design is built, the main entrypoint for commuters into downtown SLC from 700 East, Holliday, and Union Park (etc) will be via 200 South. I think that will spur much more economic development than ripping up the streets for a short-range streetcar.
I am not against streetcars. I am very happy that we have TRAX running down our Main Street and I think we need to keep building out our rail system downtown - such as along 4th South and 4th West. But I don't think building trains in the streets should be an end-goal in itself. The question to ask is 'what is being connected?' TRAX runs on Main Street because that was the best way to connect downtown to the rest of the TRAX network, where trains act like trains by running at high speeds on their own ROW. If TRAX ran as fast everywhere as it did downtown, nobody would ride it. Main Street and the rest of TRAX's 'street running' are the exception, not the rule. For a streetcar, however, the slow-going of downtown is the rule, not the exception.
Let trains be trains, and let buses be buses. But where you can, treat the buses like trains.
Here are two screenshots from the google map of my proposed downtown improvements. Black is a bridge, in this case a bridge over the railroad tracks. Red are bus lanes, green are bike lanes, and white are stations.
The BRT line starts in the bus bays at Salt Lake Central Station. From there the buses enter 200 South on their own lanes (not via a slow bumpy driveway), since the road is elevated at that point to get over the FrontRunner/UP tracks. While TRAX is in the median, the bus lanes will take the outside lanes as their exclusive lanes, with protected bike lanes separating bus lanes from the single car lane in each direction.
Side stations at 500 West would be awesome.
At 400 West, the bus lanes will switch from the outside lanes to the median. Here bus signals will detect when a bus is present at a stop light and will let the bus have its own brief phase, allowing it to move ahead of cars. It will then cross the three lanes of traffic without needing to worry about cars, moving from the outside to the inside of the road (or visa versa).
From this point on, the buses would resemble TRAX or a Streetcar in every way except for being guided by tracks. Electric buses could be used to be smooth and quiet. Center platforms would make boarding fast and easy. A high frequency would be possible, especially if a network of fast bus lines is built down 700 East. And, when the bus lanes ended, the buses could keep going and run regular bus routes. You don't need dedicated bus lanes in order to make buses work, but you do need tracks to make a streetcar work.
But these are just my thoughts, and I enjoy reading everyone's opinions here. We have the opportunity to do something cool here, what with a mostly clean slate and lots of new money to work with.