I've been working on expanding my styles lately so I've been learning Gabriel's and other's blues lessons as well as reading up on the theory behind blues so I learned about the 12 bar blues.

In A minor it is like

A7-D7-A7-A7-D7-D7-A7-A7-E7-D7-A7-E7

right?

Well I recorded myself playing these chords and it sounded horrid! The dominant 7th chords just don't work for me for some reason. Some people love the sound but they just sound so dissonant to me. So I was wondering, do they have to be dominant 7th chords? Or can you change it around and make them 5 chords like A5-D5-and E5, because those sound WAY better?

And a couple more things, is the tempo in blues sounds typically somewhere around 120 BPM?

And in the 12 bar blues is are the chord changes always the exact same? Like this

I-IV-I-I-IV-IV-I-I-V-IV-I-V

Or can it be changed to something like

I-IV-I-IV-I-IV-V-IV-I-IV-V-I

Not necessarily that, but you know what I mean.

try making the D and Echords 9th chords

Wow 9th chords sound like 50x better, I couldn't figure out how to include the 5th interval in there though so I just left it out...I think you are supposed to do that in 9th, 11th, and 13th chords though right?

There a lot of different blues chord changes, fast blues, slow blues, Major blues, Minor blues, etc...
Some songs sounds blues but they have 8 or 10 bars as main structure.

These chord changes

I-IV-I-I-IV-IV-I-I-V-IV-I-V

(or I-I-I-I-IV-IV-I-I-V-IV-I-I)

are used very often and you should consider it a kind of "basic form".

Last four bars (V-IV-I-V) are a peculiarity of the blues style.

You don't have to use dominant 7ths, majors will do, or minors, or power chards, its more about the degrees of the progression (I, IV, V etc) along with the minor pentatonic that makes the blues.

Dominant 7th chords can sound bad if you are a little out of tune as well.

12 bar as you wrote it is the traditional blues progression, but can you play other progressions? Sure, why not?

Experimtent with different voicings. Try majors\minors for I anv IV and a dominant one for V in the progression or other combinations with 9, 11 and 13 chord, less shuffled, slightly shuffled, heavy shuffled and slow.... Blues is very universal, you can play almost anything type of chord and rhythm in a basic I IV V blues progression. Just look at the signature and you will know what i mean.