My wife and son took a ride with me in the 10' Portabote last weekend. It seemed marginally more stable with more weight in it and yet was light enough for my six year old to row (not well, but that was due to co-ordination, not thrust). Re: stability. The thing tips readily, but not extremely. You have to get on in the middle to feel relaxed, but once in, it's fine. In light air, you can stand up safely. Frankly, I was spoiled in this respect by a RIB, which is like a raft.
I can see laying a lot of gear on the floor in the centerline without mishap. The boat was utterly dry. Not a single drop of ingress.
I rowed it myself for a while and being quite light, it rows very well. It is clearly superior to an RIB in this respect.
The 2 HP Honda pushed us at five knots. Not a hope in hell of getting on the plane, but I bought it so my smallish wife could hand me the engine one-handed out of the boat, which she did. She then hung it on a mount in the forepeak, unaided. I may alter the transom mount slightly as it is almost too thick (with the flap down) for the Honda and the Honda's tiller arm touches the plastic edge of the transom. I could use it 5 cm higher, and as I have a long shaft 2 HP, this should keep the prop well in the water.
It took us about 15 minutes to fold it up and lash it to the rail. I believe that a properly cut stick would hold open the unfolded boat until the first, middle seat is put in.
I am considering lashing Pool Noodles around the gunwhales should I leave it open to provide a little extra buoyancy should we load it down or should we anticipate rough sea walls, etc. Sort of a "sacrificial anode" for docking. Others apparently use inflatable collars, which I might consider for the nesting
dinghy we also have and which I have yet to sail.