Hi Minniel,
We spent a week at Waterside this past July and really loved the resort. It was our only trip to HHI so I can't comment about Egret Point. Waterside is about 2 blocks from the main beach access which could easily be done via a short walk or short bike ride. There is also plenty of shops and a grocery store at Coligny plaza which is only really one block away which was super convenient. We did rent bikes the whole week we were there and rode them pretty much all over. One thing to consider is that Waterside is not in a plantation and therefore you are not allowed access to ride bikes in the plantation unless you are staying inside a plantation. This was sort of a bummer as we wanted to ride in Sea Pines but couldn't. There are plenty of other bike trails but riding inside the plantations would've been nice.
I can't comment on the golf part as we where there to pretty much ride bikes and soak up the beach.
Whatever you decide, Waterside is a very nice resort and HHI is a very nice spot to vacation especially since you can ride your bikes up and down the beach. If I had the chance to stay at Waterside again, I would. My only regret would be not staying inside a plantation and not being able to ride bikes into Sea Pines plantation.