I think the practicality of Eglinton as a bike path is really secondary - the message being conveyed at Eglinton Connects meetings was: we can make this a better street for local use including pedestrians and cyclists, or we can make it a freeway. The LRT means that they can move many more people on Eglinton with the same amount of space for private cars *and* add bike lanes and in some places wider sidewalks. The vision goes beyond bike lanes to increasing density by giving automatic approval to projects around 5 stories for the entire length of the LRT. The renderings of the Golden Mile's imagined transformation are mind blowing.
https://www.youtube.com/watch?v=WfMgPhGr0mE
From Marlee, west of the Allen, to Avenue, the best bike route is Roselawn which connects and avoids many of the big hills in the area. But if there were separated bike lanes on Eglinton I would absolutely use them - I really enjoy biking in areas with storefronts and activity on the streets vs residential areas.