Uprading an Asus x45a?

This laptop struggles when I have more than a couple things open, and I'd like to have a fairly powerful PC that'll fit on my back. As it is now, the specs are:
Intel Celeron B380 Dual-core
4gb ram (One slot)
300gb HDD (slow)
Great ventilation, it was a selling point of this and it's noticable. Only gets warm around the one side vent.

My first question: Is this even possible? (If no, ignore everything else below)

I know how to do it, but I also know that some laptops have the cpu soldered into the motherboard. Would there be any other problems other than a voided warranty (assuming it puts back together nicely)?

Second question: If yes, what hardware is compatible?

I was looking into my cpu and it is a Socket G2 which has everything from Celerons all the way up to i7 extremes, so my choice isn't all that narrow. I assume I wouldn't want to go past the 35W TDP this has now, but would a quad-core 35W be too toasty to fit into here, something like an i5?
Could my RAM be extended past the 4gb mark? I've read that 4 is all the board supports, but is that a chipset limitation, OS limitation, or would a cpu upgrade possibly increase my maximum ram?
Finally, what would you guys say is the sweet spot for SSD price/size right now? I'd like to swap out this dvd drive for an ssd, as I saw the improvement first hand in my desktop.

Thanks in advance guys

You would be best served to look on their website and see if there is an upgrade path for that laptop and what it will actually support. It should have a CPU support list. If its not there, email ASUS and see what you can do.

256GB SSD would be the way I would go for a laptop assuming its the only drive.

Asus's website gave me very little but I dug and found the chipset, HM70. Intel's website tells me that only supports sandy/ivy-bridge pentiums and celerons. Celeron to pentium isn't much of an upgrade, so CPU probably isn't happening.

Alright I'll look into some 256gb ssd's. That'd be a big improvement. Are there any other upgrades I could make? I can't think of anything

the other is to upgrade to 8GB by adding another 4GB matching stick... curious that the laptop isn't using dual channel ram in the first place...

I haven't opened it up yet, but what I've seen on the interenet tells me it isn't capable of dual-channel: It only has one DIMM slot. Also, afaik, it doesn't support more than 4gb. I assume this a chipset limitation?

Is there anyway to improve the performance of the HD Graphics without upgrading the CPU? This stutters rendering HD video sometimes, let alone any kind of light gaming I'd like to do with it.

Do you have the full model number? X45A is series.

That would be a mainboard limitation, not a chipset limitation.

Also, just because it's a G2 socket doesn't mean the cooling solution is going to be capable of an i5 or i7.

Alright it's an x45a-hcl112g (exactly this pc here)

The cooling question is what I was asking, but according to Intel's website this chipset only supports Celeron's and Pentium's anyway, so it's a moot point.

So what I'm learning is there's really nothing I can do with this thing other than add an SSD. If only laptop boards had standard sizes xD

That's typical of cheap laptops.

Yep well damn. Thanks anyway guys, it's always you two

Replaced a X45A Intel 1.8 Celeron with a i3 2.3 SOCKET PGA988, just need to solve a heating issue and should be fine, also this setup only has 1 memory socket