Keswick, think I can help you with most of those queries,
Jogging Trail - Didn't see one as such, but did see one or two joggers on the road directly outside the hotel.
Fave restaurants - Personally, there were no stand out ones for me but the kids loved the Golden Corral and Ponderosa, however I am aware that the topic of these buffet restuarants has been debated to death elsewhere on these boards, so I won't bother here. My wife said her favourite was the TGI Front row on I-Drive right up near the junction with Sandlake Road.
Which reminds me of something else, if you go to the Virgin welcome meeting you can buy a 'kids eat free' card for $15 which is good for one child per adult ie 1 card for a family of four. Not all restaurants are included but notable ones that are include, all sizzlers, all ponderosas, Race Rock cafe, TGI Front Row (I-Drive only), Houlihans and several others. Very good value for just $15.
Towels - DO NOT PACK TOWELS for use in the hotel. There was a mountain of them left in our bathroom everyday, and unlimited free towels by the pool. You can rent them at the Disney waterparks for $1 each.
Flights - The Virgin flights were excellent both ways. We flew from Manchester on Honey Pie both ways and have no complaints at all. In previous years they flights home have been a bit bumpy, not so this year. The kids meals on the planes are barely edible, but we were prepared for that and packed sandwiches for them.
Supermarkets - Exit the hotel, turn left (towards Premium outlets) and just past the first entrance to PO is a very large Publix supermarket on the left hand side. We went there several times and the costs are much much lower than the smaller Walgreens which is about the same distance from the hotel in the opposite direction. Publix is about 3 mins drive at most and is like shopping in a huge Tescos but cheaper and with more choice.
Which brings me on to the Oakley sunglasses. Next to Publix is a small parade of shops, just one of which is a sunglasses retailer. We got chatting to the owner and he told me that all the shops have to sell their Oakleys at the same price, as dictated by Oakley, and that they regularly checked up on their retailers. A colleague of mine has a relative who works as a distributor for Oakley and she had told me something similar before we left. This is also borne out by the prices of the glasses which seem to be available in just about every other shop in Orlando, but the price hardly ever varies. The shop I have described above said he would pay the sales tax (6%) and throw in a free hard case. He does not openly advertise this fact.
I checked elsewhere and could not better his price of $100 on a pair of half jackets (nice champagne colour

) and when I bought them he was good to his word and did charge me $100 dead and give me an Oakley case which other retailers were asking $20 for.
On the last day I had a few TC's burning a hole in my pocket so went back for a nice pair of blue framed half wires (black iridium lenses

) which I had tried on at both the Mall at Millenia and Premium Outlets and been quoted $155 plus tax plus $20 for the case. He didn't have any blue ones in stock but phoned his partner who was opening their other shop that day (next to Hallmark in the crossroads shopping centre) and confirmed he had a pair and off we went en route to the airport. Glasses purchased at $155 dead including case.
The best part, the exact same glasses in the UK cost £89 (+ £20 for the case) for the half jackets and £135 (+ £20) for the half wires. Result.
Anything else, just ask as I feel like I am reliving my holiday having to think of these things.
And to everybody else (if anyone else is still reading this far - thansk for all the suggestions so far, keep them coming)