Friend, some more spoilers might be a good idea.
Some points:
Complete: Because DAMN YOU DECADE!! with the main risk being ending your series after 30 episodes with no real story
Infinity: It's more that it symbolises Haruto becoming the final hope, as the series says, and becoming stronger than the one who made him, causing problems in the plan
Kiwami: For me, it was a lot more about the loss of humanity than the gaining of power, especially considering the other parts of Gaim

Keep in mind Ultimate only shows up for one episode and is more the culmination of the idea that Kuuga's powers are dangerous throughout the show than its own thing.

Takumi was just too cool to use Blaster a lot of the time.

Was that a thing with Armed? I certainly don't remember it being major.

Liner Form was exclusively for fighting in the past once he can't use the Imajin. I've always thought of it and Climax Form as being equally powerful, but Ryoutarou is a poorer fighter.

Emperor Form is also symbolic of Wataru's arc too. It's Kiva with the chains taken off.

Complete had no real downside.

You say that about Mugen like it's a bad thing. And why does your version of Takeru talk in all-caps?

Burn.

I think Ex-aid makes Decade Complete look good.

A: Onari possessed him
B: Takeru's actor is forgetting how to act professionally again

Ex-Aid looks...Different. Decade Complete still looks laughably bad to me.

Is that one of your problems with Ghost? I think Shun Nishime has done a great job. He can really bring the emotion when the scripts call for it. Stuff like episode 12 springs to mind. Or at the end of 22 where he communicates how traumatized Takeru is from visiting the Gamma world with a simple facial expression.

Is there anyone who could make some of the lines in Ghost sound good?

Shun Nishime's really young I hear, and considering Takeru's character being rather dull, I'd have to blame either the actor, the director or the writer. Philip's actor was 16 but Riku Sanjo is great with Kamen Rider, not to mention Alphonze's VA in the original FMA anime was an actual child in the English dub iirc but I heard the VAs actually loved the source material
Norio Waka-something I think his name was? Dio's voice actor. Literally anything he says sounds godly. Same with Patrick Seitz, his English VA

Well I've never found Takeru to be dull, so I guess that explains that. If I'm remembering right, Ghost is actually tied with Den-O for youngest lead, both of them being 17 at the time. I really genuinely believe he can be surprisingly subtle when the show lets him be, though.

OBJECTION!
Philip was ALSO a lead because of W's duality, and Philip's actor was 16!
The thing is, I just don't like Takeru. There's a reason people were shocked when 40 days went by in between 2 episodes with Takeru seemingly banking on making no progress in the Eyecon hunt. Takeru doesn't DO things. He reacts to the world around him. I did like how he decided to spend his last days making his friends as happy as possible, showing he accepted death and wanted to give his friends beautiful memories. Then again lol4fakedeaths.

Also give me a single good reason Takeru didn't wish himself back to live yet

Umm....because it takes up time to draw out your upgrade device, insert it into your belt/other accessory, and initiate the transformation before proceeding to fight again. All that time taken to do that stuff can be instead used to defeat the monster who we KNOW they are capable of taking out at their current level.