I saw another post similiar to this one and I'll plagaraize the sentiment....you'll go nuts eventually by doing scales!! They're the building blocks, don't get me wrong. They're great for improv'ng, they tie everything in, but if you have "twenty minutes for scales".."twenty minutes for speed picking"..etc.. you'll get bored reallllly quick. Mix it up. Warm up playing a song you know, then doing a few scales, up and down until it's clean and smooth, then kill two birds with one stone...practice your speed/alternate picking while doing the scales. After you've done that, try learning a new song and figure out FOR YOURSELF what scale to use with it. Don't copy the lead in it...do your own in that scale. Eventually, you'll develop an ear for not only the chord progression, but what scale to use and your own licks. If you're studying the theory you should normally be able to pick up the key after the first two chords....first three at the most.