On the tab line,where the tabs should appear, tap with 2 fingers

Correct, anything under the hood can be for Mac (so far for me). Just need to reformat it. I'm using the normal essential and it works fine
Some ppl maybe don't want to know the underlying work and just prefer to plug and play perhaps. Tonnes of reason

OK I think I might have misinterpret your statement.
1) You can buy any external drives for your mac it it doesn't have to be made for mac. For example if you buy a brand new WD essential the ones "designated" for PC, you can use it for mac as long as you reformat it.
2) You can also not reformat it and you can use software like NTFS-3G or something like that to use if your external drive is using those filesystem.
3) If you have existing external drive and you wish to use it as usual on your mac then you can have the options of
i) Install the software that can read/write your current external drive filesystem
ii) You can transfer it elsewhere temporarily and format your external drives and transfer it back.

What I meant was if you were planning to buy any external drives, you can use it for your mac just that you need to reformat it to take the advantage of using journaled filesystem instead. Correct me if I'm wrong but the drives that are mac ready vs the normal one it's slightly more expensive thus I'm just informing you that almost anything under the hood is fine.
There are pro's and con's of filesystem and you may want to look that up first before deciding which way to go. For example compatibility with other system you have currently in your home, ease of not having to reformat, max file size etc.

For me I have few drives along with Windows drives as well waiting to be converted into journaled once i got another mac. I don't bother to install another software to read/write Windows partition simply because I don't use Windows at home anymore. For office laptop I got another drive which is only for office usage thus I don't mix between them.

Dead On Arrival i.e faulty when something arrived at your doorstep/when you opened it
Complete to Order i.e standard specs and not customized/upgraded specs

Not sure since I'm not into photography/videography. Based on your siggy and you question look like you are into those. IMHO maybe you can get mbp15 instead. Bigger screen since you need those plus maybe (I'm not sure) your program will definitely take advantage of those extra gc. It's all a matter of what you want in it in the end. I chose 13 2.53 last time simply because it perfectly fits my bill of usage plus the most important factor of being small and lightweight powerhouse.
My bill: watch movie, hulu, surfing, IM, some programs on terminal, normal games like Civs, Ms office, vmware with few OSes etc. Nothing fancy but most important is small lightweight powerhouse for my need

Meaning by booting up from the disc it can detect hard disk inside your mac or not