I've used S-33 quite a bit. In terms of flavour profile, I personally wouldn't describe it as a Belgian yeast. It is probably described as a Belgian as it can tolerate high alcohol levels. To me it is a fairly simple, low attenuating yeast (i.e. don't mash high or use loads of crystal as it is already low attenuating and the beer will be very sweet).
For a long time it was the yeast I used to make Milds. It really suited the low alcohol style of beer. It could probably work well in an Ordinary Bitter.
Also don't worry too much about mixing your hops, you just need to think about which hop go together. Hallertau and Cascade go together great. Early additions of Hallertau with late additions of Cascade are a really nice blend of spicy and citrus. This is my standard approach for making APA's. Also Hallertau and Fuggle work nicely with a spicy and earthy blend. Just don't try and blend too many different flavours.
So maybe go for a 3.5%-4.0% quaffer, in an English Bitter style.
Use your pale malt and and a small amount of crystal, to give a little more complexity to the malt profile. Then either use a mix of Hallertau/Fuggle or Hallertau/Cascade (historicaly English brewers used a blend of hops from different regions, including the USA, then moved to using predominantly English hops, and now a number of breweries are again blending hops from different regions).
If using Hallertau/Fuggle I would use a darker crystal as I like the richer caramel flavour against the earthy notes of Fuggle. If using Hallertau/Cascade I would use a very light crystal to let the Cascade shine on its own a bit more.
Mash at 65C, to accommodate the low attenuating S-33.
Good luck.
Cheers
MAH