1) My brewing mentor says that a brew is never wasted; no matter how badly it goes or how poor it tastes, if you learn from it. So you have learned and that's great. I had one memorable dark ale that had a very low OG, I measure in the top of the fermenter, and all the malts were in the bottom and top was mostly water. Yes, I'd failed to stir it. Once bottled
you couldn't tell any differnt, so all should be well with this brew.
2) I have used caramalt almost exclusively for some years now. Unfortunately that link to the Morgans page is out of date, they no longer make all those nice 1kg cans of dark crystal. In the past they made 2 ranges of malt; plain old coloured malts in Light, Amber and Dark, and the superb master blends range Lagermalt, Caramalt, Dark Crystal, Chocolate and Roasted Black. They have basically dropped their old range of flavourless range and now make 3 malts in the 1.5 kg cans, Lagermalt, Caramalt and Black Roasted. I guess they expect these good quality malts to take the market places previosly held by Light, Amber and Dark. Dark Crystal and Chocolate are now sadly unavailable; and it makes it harder to make a caramel free coloured beer.
So I would call Caramalt an equivelent product that has superceded the Morgans Amber. Yes, it is an amber malt; and your LHBS man has not put you on a bad path, in fact it's a good path IMHO. It will make superior beer to the old Amber - all other things being equal. One of my favourite 'K&K' brews is a can of Caramalt and a can or Muntons Yorkshire Bitter. Two cans, nothing else ( but yeast and water of course ) a real easy beginner level brew and it's a beauty. Make it to 19 litres instead of 23 and it's even better.
There are many different types of amber malt. Caramalt is the lightest possible colour crystal malt and carries a soft Toffee Caramel flavour and aroma. Caramalt is ideal for the creation of Amber Ales and light beers, where you may desire a subtle caramel flavour. It contains 60% Caramalt grain and 40% Pale Barley malt grain. Colour added 1.5kg Master Blend in 23 litres 12 ebc.
I'm sure the beer will be excellent, I haven't ever had a bad batch when Caramalt was in the ingredients' but I love caramel in anything.