I am not sure that you have thought the exchange rate thing. It is only future exchange rate movements that matter. If you borrow in Euro and invest in GBP a future gain for GBP would make the repayments cheaper, a future fall would make them more expensive. If you want to invest in property, then invest in property, if you want to speculate in currencies, then invest in currencies.
If you are living in England you must be paying some one to look after your properties in Ireland, that reduces your income.
With that level of equity and borrowing capacity why not look at commercial property. In my opinion there is a sweet spot in the Irish market above what the small time private investor can afford, below what the large investment company is interested in.