(ps: Kimika, I remember you from PF, you always gave me great advice!)
Kimika, I hear what you are saying about not willing to give the security items up.
This is really tough. I only had the dummy war where my LO insisted on having the dummy the whole time 4 monhts ago.
I don't want to give you unwanted advice, but if you don't mind, I am going to speak my thoughts, also to try and understand this whole situation of the security objects for myself.
I can understand that a child who walks around with a bottle of milk/juice during the day will cause tooth decay and prolonged sucking might even prevent speech.
A bottle during the night is also not ideal and would get rid of this like you are trying now. This is not good and I think this should not be allowed and the parent needs to explain to the child that the bottle is only for milk before naptime and then it is "finished and klaar". I know this will not be easy to take away, but a necesary task to do.
Then the dummy the same, a firm boundary needs to be put in (in a loving way

).
In my opinion a dummy at naptime is acceptable. Putting this boundary in is really dificult, we had tantrums and fights over this for about 2 weeks. I wasn't consistent in when she is allowed to use the dummy and this created a power struggle. What I did was to explain to her that the dummy is only for when she is lying in the cot. cot = dummy. If she needs some quiet time to calm down or soothe, she can lie in her cot with the dummy. THat I allow. I also allow the dummy in the car if she is extremely tired and past bedtime. Once I started being firm with this boundary (cot = dummy) things improved within 2 days. She understood what I meant and accepted this "deal" we made. In the beginning she asked me that she wants to lie in her cot for a while with the dummy when she was a bit crancky. She would lie there for a half an hour or so. Then she would call me and hand me the dummy and say when wants to go and play. This has been working great for us. I also think it is good at this age that she has a safe spot where she can go for a "chosen time-out" untill she feels better again. This is a good habit that I am teaching her, something most adults even struggle with. (The ability to know when you need to "calm down/soothe" from turbulent emotions). This strategy works for us, I am not saying that it will be the same for another child.
As for the doe-doe blanket/soft toy: Surely this holds no physical damage to the child? I know of many children who carries around a beloved comfort item for years to come. My SIL has a little girl who carries around an old nighty of her mom. (to the moms embarresment). I wouldn't take away a childs blanket/soft toy at an early age. I would hope that they would outgrow it before highschool though!
What I did find useful when she would cry for her dummy during the day, I would try and focus her attention on something else. I know at this age it gets more difficult, but it does help. I would also hold her close and give her her soft bunny to comfort her. I would go and play outside with her or even put on her favourite program for a while. I think you might need a bag of tricks ready for these dificult moments. (clay, paint, and other fun acitivities.).
As to what you said about him not wanting to play because of his clingy-ness to his comfort objects. I can understand your concern, but as far as I can understand at age 2 they only ""play next to other children" and not with other children as much. Only at age 3 they acitively start "building friendships" with other kids. At age 3 I would have been worried about your mentioned behaviour, but not at age 2 years and 4 months. What I have read is that some children are more resevered at this age and it is ok, they are still very young.
That being said, I would encourage to take the daytime dummy away and bottles, but I would keep the doe-doe blanket and soft toy.
THis is just my opinion and I know that everyones situation is different.
This is really hectic stuff. I thought I was gonna loose it when we had our "dummy war". But now that she understands the boundaries (and she still has acceptable soothing objects/habits that is allowed) she is MUCH calmer and happy! I hope it can work out for you as well. xx