My setup is in my signature.
I pulled our old fifth with a 2004 F-350. Airbags not needed. It will handle just fine without them.
Slider is all preference and depends on where you go and how you camp. If you always use pull through type sites in big campgrounds, you'll likely be ok without one. If you camp like us and end up in really tight maneuvering spots, then you'll need one.
Auto vs manual slide is preference as well. No one ever comes on a forum saying that they busted out their back window because their auto slide didn't slide. You do however see that with fixed hitches when they thought there was adequate clearance and manual slides when they thought they didn't need to. I'd be the guy that would forget to slide it, so I went with a pullrite auto slider. Been using it for 10 years with no issues in both of my trucks.
2016 Jayco Eagle HT 29.5BHDS (ordered 12/30/15, delivered 3/8/16)
2015 F-350 crew cab, short bed, 6.7L PSD, Pullrite Superglide 3300 hitch