Leaving aside all the tangents the thread has predictably taken, you asked:
What I am asking is when I am away, while I accept he will be taller and talek more when I get back will i miss much else? Will this damage his development?
Yes, you will. He will change enormously between 24 and 32 months. Just turned 2 and nearly 3 are different creatures, usually.
If he develops typically, for example:
His language will probably bloom exponentially, it is likely he will have about 50 words when you leave and be starting to join them, but be chatting away in full, though grammatically incorrect, sentences when you return.
He will become far more dexterous - going from real toddling to more like walking. His ability to jump, climb, and even hop will improve. He might learn to pedal a trike or ride a balance bike or even a real bike (there are children who do that at about 2 and a half if they have balance bikes first). He may move from eating with a spoon to clumsily using a children's knife and fork. He may go from holding a pencil in a fist and scribbling to drawing recognisable people of the circle with arms and legs and eyes and a smile variety.
He may well potty train while you are away.
His tastes will totally change. If you buy him something he adored when you left he may not be interested in it when you return.
He may not recognise you when you return and may not immediately throw himself into your arms, especially if you do not look exactly like the photos your partner shows him when you return (different hair, glasses/ no glasses, loose or gain weight, dress differently).
None of that makes it a bad idea to go though.
My father was away for 6 months working in Saudi for similar reasons when I was 4 or so - I don't remember him being away, only his return (with presents...). However he had always been very much the secondary carer (often absent because of work even when living in the same house).
I do not think it will damage your child if your child stays living in the same house with their other parent.
I think it might damage your partner if you move your mum in, but that is another issue! 
You have to handle your return well though and be the adult - do not let your child see your hurt if he does not recognise you or immediately resume your current close relationship when you return - give him time and it will come back. 8 months is conscious, remembered life time to a 2 year old.
Also be prepared for the fact he may refuse to talk to you on the phone (nothing personal, lots of preschoolers wont) or may take the phone and prattle away using words and sentences that make sense but that you cannot follow because he doesn't realise you don't know the intimate details of his every day life so can't follow his stream of consciousness.