I think a 2Ghz CPU might be a bit slow, Minecraft is very depended on single core performance, through 3,2 GHz is enough. Vanilla MC can do with 1Gib of ram, but mod-packs require more. MC1.7.10 mod-packs generally need 4Gib or less. MC1.10.2 mod-packs generally need double the ram of a similar 1.7.10 mod-pack (so 8Gib or less)
"Needs 8 Gib" means: 8 Gib for minecraft, plus even more ram for java, plus even more ram for the Operating system. So if a pack needs 8 Gib, and you have 8 Gib in you computer, you do *not* have enough. So stick to packs that need at most 6 Gib.
Graphics cards are indeed not needed for minecraft. However, making use of the on chip graphics does impact the performance of the rest of the CPU, so having dedicated graphics does still help a bit. Also, if you use a HD texture pack, a good enough graphics card will be needed.
I read 'dedicated' graphics as 'integrated" graphics, as any card installed in a system is 'dedicated'
The biggest drawback of Integrated graphics is they are a drag on system cycles, which lead to slower speeds than you would expect. By this I refer to the fact that while the graphics is accessing shared ram the CPU usually goes into a wait state until it can access the ram again, and vice versa.
"Shared" ram means that although you might physically have 8GB ram installed in the system, between 1/4 to 1 GB of that is not available for program use because it is reserved for the Integrated graphics. With a separate GPU the video card has it's own dedicated ram to play with, allowing the CPU to continue with it's tasks at full speed.
For example, I would never buy a laptop to be a primary gaming machine... To start with, the chipsets are optimized for battery life and therefore generally slower than their desktop "equivalents". Secondly, since the only upgrades you can generally make to a laptop are ram and disk amount, there is no upgrade path for CPU or GPU.
There are two, maybe three laptops out now with full desktop chipsets and top of the line GPUs, but who wants to spend over $3000 for a laptop? Or, in one case, extra $$$ for the portable water-cooling docking station to allow it's best performance?