Yes I believe doing tax/accounts yourself is simple if your tax affairs are simple. All the online book keeping software nowdays is quite sophisticated. I just have to type in what I bought or sold.
The VAT I pay each quarter is just a sum of the VAT I typed in on entry. So generating and submitting the VAT return is literally just one click.
End of year tax is just the difference been costs and sales (profit). In the UK, HMRC, provide you this PDF form where you input the total sales etc, they calculate the tax for you. So it really is just form filling.
I believe being a native Belgium there is nothing stoping you from forming a UK company, nor taking it's profits back to Belgium?