Intel Mac :: Iphoto Lost All Photos / Request To Server Failed?

I have a 2011 intel iMac. It is the (supposedly) powerful 3.1ghz i5, and i upgraded the RAM to 12 Gig. Before buying this machine I had a 2008 iMac and LOVED it, it was superb. But this machine is SLOWER than that one was?! I am running OSX lion, iLife 09 and iWork 11. I am having a nightmare with this machine, it hands constantly, i only have a few apps open and still it can take 5-10 seconds (beachballing) for finder to draw my files when i open a folder. This can't be right. I have reloaded the entire machine from scratch twice by  cloning files off and then MANUALLY rebuilding it (not using Migrate Assistant to ensure to i was not bringing any bad data or bugs across from old installation or old machine). It is slow as a dog, way slower than my old iMac which had a mere 2 Gig of Ram! If i open more than 10 browser tabs in Safari it goes so slow I can't use the internet. The machine crashes at least twice a week and just hands so I have to force shutdown, and my latest error is iPhoto just lost ALL my photos, 5 years worth and gives the error "Request to server failed" but says nothing else of any use. I am hoping to recover them with TimeMachine but wait and see on that score as nothing seems to be right with this machine so no doubt TM will play up as well.

I have VMWare Fusion installed, latest version. It does seem slower when running that, but it still crashed and plays up when that is not running so I am sure that is not the source of any problems, it just makes them a bit worse due to processor usage.Is it possible to get an iMac diagnostically checked (hardware) at an Apple store? It is still under warranty this machine, but I can't drop it off at a store without wiping all my data (clone) to external drive, because I have confidential information stored on it which I can't leave on if the machine leaves my office. I struggled to afford to buy this machine, and thought it would sky rocket my performance and speed after my old machine started to get slow due to age, but even at its worst it was never this bad. I am now a very very disappointed Apple lover, ex-lover?! One final point I should mention, I upgraded the RAM myself, using proper stuff from Crucial. I read that it didn't matter what order the RAM cards were fitted in, is that true or should I try moving them around? 

Info:
iMac, Mac OS X (10.7.4), 12 Gig RAM, 3.1ghw i5