As a parenting educator, I can tell u that time outs don't always work for this age. Although, if you do decide to send him to his rm, you must be consistent. Consistency is key. I always turned my daughter and held her until she stopped.
What has been happening is very predictable for him. It's time to turn it around.
If he kicks...Pick him up immed and turn him facing out and tell him that kicking her hurts and it's not ok to kick. Hold him tightly (without talking)for a few minutes until he calms down. Then, move onto something else.Or take his fists and do the same thing. PLEASE, change your voice to a stern one when he displays these behaviors so he (also) hears the difference. Changing your voice is very important as he is only 2.5.
Do not lock your self in the bathrm. Rather, keep your cool (sometimes it's sooooo hard) & do what was mentioned above. You will need to do this several times to change what has been going on. He is 2.5 and needs your guidance.
If at other times he has a tantrum and falls to the ground to kick and scream--Walk away and ignore it. This is his social/emotional growth taking place.
Keep him on a routine the best that you can. Structure is quite important.
If he is not sleeping the required hrs each night, these behaviors will stay the same.
Also, try taking him off of all or anything artificial --flavorings, drinks, etc... This could be a contender. Our food is extremely processed.
No dyes, corn syrup/HFCS, diet anything, possibly wheat, etc...or an excess of cane sugar. Look at cereal labels, juice labels, etc...I switched my kids over to organic cereals when they were young.
The only other thing I have to say is that I have worked w/ hundreds of families. Keep an eye open to having him being evaluated, if needed. I am reading that he gets more aggressive when he goes outside. Hmmm. But, I am not there to see how the day is structured.
When he hits and you go in the bathrm, he gets all tense. From now on, be the active parent and be firm using the method above. He needs to be taught to learn self-control. And w/ "spirited" toddlers it can take many, many, many attempts.
Feel free to let me know how things are going ! Send me a message any time.
Every so often, set out a new toy and let him get curious and play w/ it for a few minutes. This way he will learn a tad of independence (as much as a 2.5 yr old can have the attention span for) to help break what has been taking place.
My 1st one was "spirited". It's been a journey !!!
Sometimes it's their temperament and sometimes they need to be evaluated.