If I don't claim my Post/Comment rewards, is there a time limit to claim them? Will the rewards ever dissapear or I'll be able to claim them even 1 year later?
There are times I don't claim my rewards for up to a month, many times, even more.
Because of the way the Steem blockchain is built with transparency, some people tend to spy on you and so that's why I do that.
So far, there is no time limit to claiming rewards. It is yours, so even if you do not claim them for a whole year, they will remain as long as your account is still intact.
Rewards you earn on Steemit are stored in your wallet. They don't disappear. They accumulate and pile up if you don't claim them. It is always advisable to claim your rewards and save into your wallet.

Also make sure you save your password or account key to avoid scammers transferring your rewards away from your account into theirs.

No there is no such limitations... If you stop claiming your rewards they will just keep adding up in your wallet.. And there is no limit on how much rewards keeps adding up..

If you are new to steem or that you just might not know that you can allow certain dapps permission to collect the rewards for you. For starters you can use steemauto.com.. Here is a step by step guide on how you can do that-

* Open your browser and type in the url steemauto.com.
* Click on login.
* It will redirect you to steemconnect.
* Choose the account with which you want use the auto claim.
* It will take you to steemauto homepage. Then go to dashboard which you will find in the left menu.
* When you are in dashboard you will find an option labeled as "Claim Rewards"
* Click on it and it will take you to the next page. Where you will find "Click to Enable" Click on it and you are set.
No, there aren't any limits concerning how often you can claim your rewards. I claim my rewards on a weekly basis because I can integrate it into a financial system that works for me.

Claim your rewards at your own convenience. If clicking the claim button is a chore, there are days that you can use to do that for you.
I believe others here have already answered your question. I would like to say that it is not a good idea to stay without claiming the rewards. We end up in a loss if we don't claim the rewards and power up. The little opportunity for growth here in steemit is only through power up. If we don't power up the rewards, there is no use in holding them without claiming.

Some people even say that we have to keep buying and selling STEEM regularly with your SBD based on the price fluctuations to earn some profit here. If we keep the rewards without claiming it is not going to help us in any means.
Till now there is no any limit to claim your post and comment rewards in steemit.if you don't claim your rewards then it would be your loss because if you do so then the price of the steemit increase and decreases going and you will too much loss due to this .

If you don't claim then there will no reputation score increase and also you cannot get good amount of upvote and you can able to earn more money.if you don't claim the reward you cannot convert your earning to sbd and also your balance remain constant.

The rewards you get in steemit will not be disappear even if is 1 year or more because there you see a reward claim option and you can redeem the claim bonus anytime when you are free so don't worry to claim post and comment reward but if you redeem it will be beneficial to you only.