If the charging receiver (the main source of heat in wireless charging) is on the rear cover, and not touching the battery, it can get a lot hotter than if it's an aftermarket receiver pressed against the battery. If it's one of those external "plug into the charging port" receivers, it's almost moot, since most of the heat from the receiver will dissipate in the air. The temperature we're concerned with is the battery temperature - the receiver can get hot enough to melt its solder joints, as long as the battery stays cool.
The permissible charging temperatures - at the battery - are 0°C to 45°C (32°F to 113°F). For best results, charge between 10°C and 30°C (50°F and 86°F) - at the battery. (That's the temperature you'll get from battery temperature apps.)
Qualcom "fast charging" is actually normal 1C charging. (Most phones charge at well below the normal rate.) The battery lifespan is probably measurably less when charging at 1C than when charging at 0.3C in the phone, but you'd have to run identical batteries through months of testing to measure that difference - it's small. Wireless charging is normal phone charging (my phone charges at 1200mA from the wall charger, and 640mA on wireless or USB 2.0) - the only difference is the heat absorbed by the battery from the charging receiver. If that's kept low, the effect is negligible. (I've been charging my Note 3 both ways for a long time - wireless when I'm charging overnight, to save wear and tear on the port, wired if I need a fast charge before going out - and I haven't noticed any degradation in battery capacity. And the receiver is pressed up against the battery.)