I think those are more balanced. Personally I think it should apply to all creatures summoned by a spell, so a druid could make it work on summon nature's ally, or a wizard with a gate spell.
I also think the progression shouldnt be 1st level, 5th level, 9th level. Maybe 3rd, 10th, 17th. I don't know why you think its bad that a feat that only affects conjuration (summoning) spells can't be taken till 3rd level. A first level caster with a summon spell is pretty silly as it will only last 1 round; its silly with some bonuses, or without. I certainly wouldn't think about taking such a feat until I was 3rd level, and even then I would probably wait till 6th.
The reason I said the str and dex bonuses were unnecessary is because I went through the trouble of statting out some creatures using your feats and adding the extra str to all the attacks and the dex to ac, reflex saves, initiative, and possibly ranged attacks seems very cumbersome. If you want a summon monster to have better ability scores, cast the appropriate buff when you summon it.
Technik
I also think the progression shouldnt be 1st level, 5th level, 9th level. Maybe 3rd, 10th, 17th. I don't know why you think its bad that a feat that only affects conjuration (summoning) spells can't be taken till 3rd level. A first level caster with a summon spell is pretty silly as it will only last 1 round; its silly with some bonuses, or without. I certainly wouldn't think about taking such a feat until I was 3rd level, and even then I would probably wait till 6th.
The reason I said the str and dex bonuses were unnecessary is because I went through the trouble of statting out some creatures using your feats and adding the extra str to all the attacks and the dex to ac, reflex saves, initiative, and possibly ranged attacks seems very cumbersome. If you want a summon monster to have better ability scores, cast the appropriate buff when you summon it.
Technik