I don't think it would matter =/
Since in the end, either way you are going to reach the "total" i.e. if I removed 5 marks from an essay worth 10 marks, I would end up scoring 5/10.
If I added added 5 marks from an essay worth 10, I would still get 5/10.
My point is, nobody would be able to provide an answer since it really depends on the examiner I think, and not something to worry about ><
One thing which sort of is related to your question, I have heard that in the English exam, examiners quickly glance at all your pages, skim through the first paragraph or two, and are then able to estimate what your piece would be worth, does that make sense? Because many high-scoring responses tend to maintain the same level of skill and ideas throughout the essay, it's what makes a good writer!
Then again, many people tend to start off terrible (hence make a bad first impression), and then once they get into the flesh of their essay and conclusion, they write very solidly/well, yet that first impression would have dented your overall marks slightly e.g. a 8/10 instead of a 10/10.
English is subjective in regards to your latter question. Different people can get away with both.
I have never seen a "simplistic" essay in the examiners reports, but I have seen essays which are no better than what I already write in SACs, (making them simplistic??).