1st, I would make the seats more comfortable. Then,retract all routes outside of Ireland, so that it is a true Irish carrier. Next, I'd add at least 1 premium cabin. 4th, I'd add a second type of aircraft for long-haul (airTran did it with 737/717, and NAS is about to with its Dreamliners [Assuming they'll actually work ] and A320neo's ). Finally, I'D Buyout Aer Lingus to make the ultimate Irish Airline!!! Whahahaha! Anyway, You get the point, the BA/AF/LH of Ireland.
1) That would cost a lot of money and seats might be bigger then and take up more space reducing the number of seats on the plane.
2) That wouldn't be a great idea for such a huge airline now would it?
3) Then it wouldn't be a low-cost airline. O'Leary wouldn't allow this because it would reduce the airline's profit margin and therefore reduce the share price of Ryanair and that would be a disaster
4) Low-cost airlines don't do long-haul because you just can't run low-cost long-haul flights
5) Aer Lingus won't sell. Ryanair have been trying for ages to buy it out and have offered 1.5 times the share price but investors still wouldn't sell.