I could not disagree more!
Attention to minutia is what you have a Greek accountant and a Greek lawyer for!
Mere mortals such as you and I with UK business backgrounds will never understand Greek business ways and methods so don't even try; employ an expert, you will need them anyway to sort out your tax affairs so make them earn their money.
In the UK 80% of new businesses fail in the first two years so I would rate your chances of succeeding here as just slightly above zero, and that would be if you had a Greek co-director/partner.
Brits fail to make it abroad because they think it is easy, they see a laid back Greek who appears to be doing well and think that they can be the same. They can't. They are broken by little differences, not the big things. For example, in the UK you have, if I remember the name correctly, "The small business late payments act" which gives you some chance of being paid on time. No similar act applies here, it is not unusual to wait 6 or 8 months to be paid, do you have the capital funds to finance this bearing in mind that, if you are importing, your supplier will demand prompt payment? You may have the best product in the world, and people fighting to have it, but if you cannot get paid you are stuffed!
Muttly, you don't need to earn, save yourself the agrovation and just relax in Crete