If you pay out a salary, you can reduce the company profits. So if you live in Dubai, it wouldn't really matter where you incorporate if most of the profits are paid out through the salary anyway. Just beware that the tax authorities may say that not 100% can be paid out as a salary and that some has to be paid as a dividend instead - so the company would have to pay tax.
You may be able to avoid that by registering a branch in Dubai, but you should talk to a tax advisor from the UK/Estonia about that.
Estonia might be a bit easier to deal with as there definitely is no tax due on profits that are kept in the company.
Portugal only exempts dividend income from tax, so you would always have to pay 25%/20% corporate income tax. You would be better off using a Maltese company where the corporate tax rate is only 5%.
I'm not 100% sure about the rules for Cyprus/Malta.
Anyway, in the case of all the countries you mentioned (except the UAE), there's always a risk that they will tax your company like a local company. You can't simply avoid taxation by incorporating somewhere else. It could even be considered tax evasion if you don't declare that, so you should talk to an advisor from that country as well.
If I were you, I would first try to decide where I want to live. Once you've decided that, I would talk to an advisor from that country about what kind of setup they recommend.
E.g. if you like Portugal, there are dozens of companies that will register a company for you (typically in Malta/Cyprus), accounting will be done by their partners, and you just get a complete, hassle-free solution.
The only downside with Portugal is that there is some risk, like I explained above. But at least you will be one of thousands with such a setup, not a lone guy with some weird structure nobody else uses. It's well-tested.
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