2004 Cadillac Deville passanger front end tire sakes although a rotated tires and got alignment 25 days ago.

I would be checking out the wheel bearings for the problem. I would also be checking the front suspension for worn ball joints and steering end joints. Tyre wear patterns indicate unbalance-wheel alignment-shock absorbers and front end wear. I refuse to rotate tyres for several reasons Radial tyres when developing a wear pattern will retain that wear pattern even if placed on a trailer--Wear patterns show a fault for that wheel and tells which wheel and what needs to be done to repair it and lastly tyres wear in pairs so if you have a front wheel drive car why replace 4 tyres when the need is to replace only 2 front ones. Saves about 50% of the cost of tyres. The rotation theory came about from cross ply tyres and does not apply to radials except for tyre dealers profits

A bad rotor would only cause a shake when you are using the brakes. A bad tire could shake at 55mph and above.
I would get a second opinion to make sure.
The shop could rotate the tires and see if the vibration moves to a different area of the car.

Cars and trucks are supposed to have their tires rotated every 5,000 miles.
Doing this will only slow the wear on the outside of the tire. Whenever you turn a corner, the weight of the car and the forces of friction will cause the outside of the tries to wear off, the rubber is getting "scrubbed off".
Not rotating the tires will cause the outside of the front tires to wear out before any other part of any tire.
Then, there is the matter of worn "front end" parts.
The parts that wear most often and quickest are the tire rod ends. Next are the ball joints, and last are the shocks/struts.
When a car has about 100,000 miles, these parts begin to show their wear by causing bad tire wear.
Someone needs to check your car most carefully to see if any of these parts are causing your problem.
After all the worn parts are replaced, the last thing is the "front end alignment".
As you drive mile after mile, you occasionally hit bumps.
Although these bumps do not show up quickly, the bumps will, over time, cause the tires to become a little crooked, and about once every 3-6 years, the front end needs to be aligned, or have the tires straightened.
Be blessed.

4.5 liter fwd in the front in the middle between engine and trans axle rwd it would be passanger side located by passanger front tire.

Check your strut mounts, and front struts, my 2004 cadillac deville did the same thing between 67 and 75mph and after time it shook between 58 to 80mph, and it was the front strut mounts were egged out, and front struts were weak. I had my tires balanced, wheel bearings replaced, and it didnt help.

Tire wear as you outlined is caused either by incorrect toe in or camber setting. Both are components of wheel alignment. Regardless of what you were told, there is no other way that happens.
As to who gets to pay for it depends on your agreement.

go to another mechanic or front end shop ur mechanic may not have the proper equipment to do alignments

you need an alignment. Its a toe-in, your tie rods need to adjusted. Check your tire pressure too.

once a were pattern is worn in tire s unless you rotate tires to the rear they will keep wearing you should rotate your tires every oil change especially if you do alot of around town driving i am willing to bet you that good year lied to you about the alignment i am sure the dealer put it into spec the first time you just need to rotate them a little more often

on the wobbly have the tires inspect for posible broken belts, or rotate the tires and if gets better that means you have broken belts on one or two tires and need a new one, and on the poping just have it inspect for an auto repair, you can fin one here for your area in the home page just look for services and type your zip code