The normal route from Beddgelert does start quite steep up to a gate in the intake wall, then it eases off a bit before steepening again through some very mild little scrambly bits and working it's way through the upper levels of crag bands, where there are some unusual "cannonball rocks" to be seen.
For navigation ease I'd probably recommend returning the same way. The route back over Moel Yr Ogof and Moel Lefn is very nice and can incluse some old quarries but does leave you with the forest tracks to content with (ok with an up-to-date 1:25k map and a bit of concentration).
The potential descent to the SE starts well, but if you try to get down to Aberglaslyn the path disappears for about a km into an area of trackless bog, which is a shame as the return to Beddgelert through the Aberglaslyn Pass would round off the day really well. There is another track shown on the map coming northwards across the hillside back to Beddgelert but I've not followed it yet so can't say what it's like on the ground.