Hello Lin
I will try and answer the questions you raised.
If you look at many of the Asda store buildings they usually have three sides that are just plain (usually white and looking like a sort of corrugated iron) walls, the Newton Abbot store is like that to a large extent. Like their American parent company Walmart stores, they are not striking architectural buildings, just great big sheds. If you have Google Earth try looking at some towns that have Asdas. You can spot the stores as great white sheds from miles off - try Spennymoor near Gateshead and you can perhaps see what I mean. See also
http://theblot.wordpress.com/2006/09/16/asda-blunder-in-newton-abbot/ for one Newton Abbot resident's views on their Asda building.
It isn't true that those opposed to the use of the estuary side don't have alternative ideas, they just don't get much publicity afforded them. I have already mentioned the London Inn as an alternative, some have suggested a store on the KFC roundabout (not stretching from the estuary site though) indeed the Town council supported that idea, an improved Sommerfield would help and also perhaps something could be done in the area at the back of Sommerfields and Boots. There are many rumours that the Post Office is to be sold and that site could make a good store of a more suitable size.
When I went to the Tesco presentation I talked to one of their people about the presumption that a bigger store would make for better shopping. In some places I know as the store has got bigger so too have the crowds and in the end there isn't much real benefit, often quite the opposite. It is a bit like building new road, the more roads you build the more cars come and fill them up. I was told that they did not expect to draw many more customers as there are not that many places to draw them from, but that they expected shopping to be a more plesant experience. Their words not mine. It begs the question though, if Tesco don't think there is enough extra business in the area where are Asda's customers going to be coming from? Exmouth is not a typical town, three quarters of the area surrounding it is water, either the estuary or the sea, and thus the catchement area is restricted to a quarter slice of the normal cake. Even in that quarter you don't have to go too far out of Exmouth before it you are closer to Exeter and its greater range of shops.
By the way, the Tesco exhibition is on tomorrow Sat 10:00 to 16:00. Don't expect too much though, it is really just an artists impression with explanations as to the changes they want. There are Tesco staff there to ask questions of though.
As to where to start a group Lin, I think it is a question of finding like minded people who are willing to give a lot of their time and some of their money to enable others with similar views to join them to debate the issues and take things forward. It can be hard work, time consuming and extremely frustrating when you are up against 'the system' and all the interested parties. (Exmouth people taking on Asda Walmart, the worlds largest corporation, is really a David and Goliath scenario.)
I do recognise that Exmouth hasn't got everything that its inhabitants may want in terms of shops - I suspect that you cannot get your childrens clothes here and would appreciate a George outlet. I was in Exeter myself shopping for clothes, and books today (the book was one Asda would never stock and I doubt that they would have my size and _style_ of clothing). I think though that we must accept that Exmouth shops will never meet all our needs, there will always be reasons to go to Exeter or somewhere else for some things. What we should be able to do is get most of the things we need in our daily lives in Exmouth and at the same time have a town centre that is a vibrant and pleasant place to spend time in.
I hope some of this helps understanding where I come from and why I hold some of my views, and that I am trying to take on board your views too. Again, I am sorry to have gone on!