I'm looking for a laptop myself for online classes / some gaming / youtube and movies. The first link you posted the asus looks pretty sick not going to lie. I might buy that one. Experts please post what you think of these links and give us some suggestions!
Yeah, the CPU is pretty weak. Then again, many times you get what you pay for.
I recall someone complaining that AMD E series was too weak to play the Sims 3 after installing one of the expansion packs.
I'm now using a A8 but i had a E-350 laptop and it was ok for sims 3 on low-medium settings but when you start adding lots into the game it slowed down quite a bit. Either way the E-450 should be ok for those tasks.
The Llano based E series is a weak CPU (E-300, 350, 450). They're good for HTPC's, but that's about it. If you want to game on a laptop for ~$350, you'll want either a trinity based E series (e.g. E-1200), or a Llano based A series.
A-3xxx are Llano based chips (older hardware), A-4xxx are Trinity. Long story short, the trinity chips are better.
The Gateway and the Lenovo are the better choices.
The Gateway Machine has a more powerful processor and a bit better graphics hardware for cheaper; but it is a refurbished machine.
Lenovo generally has better build quality than gateway, though I can't speak for these specific models.
Personally, I wouldn't buy a refurbished machine unless I was sure of the repair technician. If the gateway machine works, it's a good deal however. Newegg has a solid return policy if it does go bad, though you'll need to pay return shipping.
Asus has a better rep for build quality and customer service than Acer. Unless you really want windows 8, I would get the Asus.
* they have a slightly different setup. The Acer has 2 USB 2.0 ports and 1 3.0; The Asus has 2 USB 3.0. The Acer has a more current version of bluetooth. Asus machines have less pre-loaded crapware than other manufacturers.
Any of those machines will perform non-gaming tasks well and the E-450 and E2-1800 will run modern games at 15-30 fps at low settings. Benchmarks are not reliable indicators of real world performance and never were. They are indirect measures that may or may not indicate real world performance. A video of a system in use is worth a thousand benchmarks.