Feeling or skill ?

It takes both. All the feeling in the world won't do much good without at least some fundamental knowlege of lead playing. It doesn't take a whole lot. You don't even have to understand why things work but you do need to know what works and how to do them. Feeling is what makes the solo yours.

"Nobody paints by ear so why would I play guitar by sight?"

You've got to have the feeling, all the skill in the world won't matter if the solo lacks feeling. Think of the solo as a song within the main song, a tiny symphony. There are some very effective simple solos, Buddy Holly's 'That'll Be The Day' does a few chords and then repeats the song riff, but Buddy makes it sound exciting, commanding and every bit a real solo. Thats feeling triumphing over skill, Buddy played it like he meant it.

When playing music, it isn't just what you say with the notes it's also how you say it. At the same time if you say something completely incoherent it's not gonna make much sense no matter how much emotion you say it with.

"Nobody paints by ear so why would I play guitar by sight?"

True James but most people have trouble understanding minor and major scales. I recommend learning the basics before acquiring scales that only fit off-beat jazz stuff.

I've been playing nearly four years and still don't always 'hear' the modality first off. Got myself in a real pickle last week trying to play a minor tune bassline with a major triad!

Major and minor scales *are* the basics.   They are the foundation for just about every modern guitar piece you're going to play,  and the foundation for any solo you're going to play.\

People think that they can get by on "feeling" and not understand how to manipulate the fretboard are never going to be able to play the guitar well.