My, what a tall order. I must confess that nowhere springs immediately to mind that fits ALL your requirements. The best thing is to use the Search facilility in the Eat & Sleep/Accommodation section to give you a broad list. You can refine it from there then come back to the forum with questions on specific properties.
Based on your requirements, though, I would just make the following general comments:
a) Unless you stay in the built-up Crown Point area, or in one of the villages (Castara, Speyside, Charlotteville), very few places will be within walking distance of a choice of bars/cafes.
b) Pretty much everywhere on the Caribbean coast will get sunset views. Even properties on the Atlantic side can benefit from lovely sunsets as the sun sets over the hills behind the property.
c) Our property lists will tell you how near a decent beach the property is. Please note that VERY few small guesthouses - particularly those outside the Crown Point area - have pools.
d) That's not that many historical buildings you can explore without extensive driving around. Scarborough is about the only place.
Have fun searching and come back any specific questions.