Can't make many comments on Chermside but the biggest issue with Upper Mount Gravatt is how car infested it is. Both kids and cyclists have been hit on Klumpp Road. It is near the V1 Veloway (the noisy, less pleasant part compared to the Woollongabba-CBD stretch) but otherwise has pretty poor cycling infrastructure.

My high level suggestion are:

More bike lanes and bikeways. Connect up the Bulimba Creek bikeway to the Veloway - either needs a new bridge over the motorway or bike lanes on and around Kessels Road.
Walking access to the Upper Mount Gravatt busway bus stop should be improved. Wider, flatter footpaths with more trees, reconfigured traffic lights. Do some user testing.
The Griffith University stop on the busway should be moved southbound to the Park 'n' Ride at Klumpp Road, especially now that Mt Gravatt campus has closed. This would benefit Hibiscus, the local schools and sports club as well.
Dunno what to do about the hellscape that is Logan Road and Kessels. Kessels Rd is a major arterial road that trucks use to get to the Gateway Motorway/Port of Brisbane. Maybe long term improvements to the rail network so that freight have separate tracks?