MostEd, generally you just need to practice a lot. Try to combine EO and Line as often as possible, even if it takes >15 seconds. If you do this for several months you should eventually be able to consistently plan EOLine in sub-15.
ya if it's EO then you have to make sure that all the stickers on the U and D are the same or opposite colors of each other. if they aren't then you're not finished with EO. if you think it's UL/UR then make sure you're doing the right moves. you can only do (M' U2 M'), (M U2 M), U moves, and M2