What is a typical glide angle for a modern passenger jet with engines idling, with full flaps and with the gear down?
It must be in the region between 1/5 (11.3°) and 1/10 (5.7°), and closer to the shallower angle. I guess you want the value at 1.3 times stall speed - without a speed an answer would be impossible.
Once the glide ratio drops below 1/5, the energy dissipation is too quick to allow rotation for a soft touchdown with idle thrust. On the other hand, a glide ratio much in excess of 1/10 will make the aircraft float along the runway in ground effect, which makes the precise selection of the touchdown point (at the correct touchdown speed) hard. Spoilers help to adjust the glide path angle to steeper values, so the aircraft with flaps and gear fully deployed but the spoilers in should have a glide angle around 5° to 7°.
Depends on the requirements of the approach. A typical PAPI or ILS glidepath is 3.5°. But some non precision as well as precision approaches are steeper. The LOC/DME-E for KASE has a steep final approach angle of 6.59°.
Peter's assessment of glide angle is good as well, though one might be able to fly a little steeper with judicious use of power when entering the round out to arrest the descent.