So lost in blues

I just want to say Hi and Welcome to Guitar Noise.
I am not sure how to answer your question and soon you will get a better answer but I will take a stab at it.
Play in the key of the song, don't worry about chord changes.
If the music is written right, all of the notes in the key the song is written in will be the same notes the chords are comprised of.
So what I am saying is a blues pentatonic scale in the key of D for example will fit with any chord used in that key signature.
The trill thing. All I can say is practice practice practice. I can trill for about 2 beats now, a vast improvement for me. My brother in law can trill indefinitly or at least until his fingers cramp. (it does amaze me when he does that)
A little example to clarify.
You are playing in the key of C and someone is playing C chords, you are playing a C scale over the chords. Then they switch to a G chord (the notes the chord forms from are from the G scale but the notes in the chord are G,B,D) the same notes you are already playing in that C scale, swtch to Am, same thing.C scale still fits.
If for example you played a scale in the key of G when the G chord started playing you would at one point play an F# and F# doesn't belong in the key of C that the song is in.

Definitely the easiest thing to do is to stay in the blues scale of the I chord all the way through. You CAN change to the blues scale of the IV or V chord root note while those chords are playing, or even change from the minor pentatonic or blues scale of one chord to the major pentatonic or "traditional blues scale" of the next chord when the chord changes. That's fancy stuff and can get you lost.

That's fancy stuff and can get you lost.

Yeah think of it as extra options that you can go to if you need a little extra something.Like maybe during a solo or something or to find the occasional sweet sounding note or bend,etc.But for phrasing you got the notes in the chords and the minor pent or blues scale of the I chord all the way through which should be pretty good for coming up with hooks or vocal type phrases.Blues guitar often imatates the singer,or vice-versa.That's something Zeppelin really exploited,I think we can safely say.

Personally...

i think trills are very easy, its the volume of the guitar...

Like listening when people trill, its probably recorded, and guitar volume is very high but it comes through easier, when the guitar volume is high you can touch and tap and make the sounds of the notes come out that you wouldnt be able to hear when the volume is down.

so volume up and trill and it will stay clear for, lets say... years..

........also partly to do with finger strength, if a finger gets tired and moves slow, its gonna choke.

My last teacher was really into the blues and we spent a couple of weeks doing exactly what you are struggling with. He played the chords and had me solo over them. The important thing is obviously to stay in key but to also try to solo over the appropriate chord with the appropriate notes and to stay in time. For example, in your E A B example, you're playing the I, IV, V in the key of E. You could solo using any scale in E but would probably be best off using Em Pentatonic. In the first measure (E), start your solo on the root. When the chord changes to A (2nd or 4th measure probably) try to hit the root of the chord (A) on the first beat of the measure. Likewise when the chord changes to the IV, try to hit the B in your solo on the first beat of the measure. It may seem mechanical at first but it's a good way to keep your solo sounding like it fits with chords. (It's also a good way to let everyone know that you know what you're doing!)

Well, it's optional. A lot more blues has been done with the solo all in the root key than changing with the chords. Both ways work. And both are done by folks who know what they're doing.

I think my post may have been confusing. I wasn't recommending changing keys. Continue in Em but get to the root of the chord on the first beat of the measure. You can do that without changing keys.

I think you question was answered. think about it a bit.

I know what you are feeling. I felt so stuck. same old same old.

that changed when I thought of it in the terms as posted above.

another cool thing , as was posted, is to go up the scale in a major but descend in a minor.

moving up and down the neck also will help change your voicings.

the scale from the open E chord on the lower frets are awesome when the notes are bent and held. then walk that scale up the neck towards the seventh and nineth frets (theres an E scale there too). then up further to the twelve fret then up again . those octave shifts are great.

two of the most important things Ive learned by sucking at blues licks is to play like the notes are a voice singing. and the other and the most important is to

play with feeling.

I think you question was answered. think about it a bit.

I know what you are feeling. I felt so stuck. same old same old.

that changed when I thought of it in the terms as posted above.

another cool thing , as was posted, is to go up the scale in a major but descend in a minor.

moving up and down the neck also will help change your voicings.

the scale from the open E chord on the lower frets are awesome when the notes are bent and held. then walk that scale up the neck towards the seventh and nineth frets (theres an E scale there too). then up further to the twelve fret then up again . those octave shifts are great.

two of the most important things Ive learned by sucking at blues licks is to play like the notes are a voice singing. and the other and the most important is to

play with feeling.