Hi Naz,
I think we are back to time frames again. Sure, if I wanted to succesfully trade UK or US stocks on a daytrading basis, then L2 would be one of my prime tools - along with the tick charts. But on a slightly (and I mean slightly!) wider scale, if the big players want to buy and push the stock, then they will be wanting to give it some momentum which we can then ride - l2 in this case becomes less important, if they are interested in buyng ot take profit, then they will not really want to push the price too hard, and the chances of it breaking resistance or support is less. If they want to spike the stock to gain an advantageous sell position, then they will try to do it with as little volume as possible.
So it all adds to the grist and whether you use L2, L2+chart, L2+ news or no L2 at all, comes back to the time frames and risk/reward ratio - for a chartist, buying and selling on trend/sup and res is as valid if you are trading intra day or longer periods. Personally I trade a mixture of tick charts and longer term positions, none in individual stocks, mainly indices, commods, bonds and currency, all basis futures.
Cheers