No. You can share or send as many posts you want, but once a person marked a post as seen, s/he can't interact with same post twice.

Unlimited.

Once you earned some reward points, Just apply for withdrawal option in app you installed. The amount equal to your reward points will be sent your Paytm Account within 24 hours.

Posts shown in Adrain may be region specific. If a post is for specific region, only person belong to same region can share or reply. So, You need to update your profile along with your region.

Consider following example.

1. person A shared a post with person B.

2. B replied to post shared by A

3. B shared same post with persons C & D.

4. C & D both replied to post shared by B.

In above case Person B will get
1. replier's reward credit for reply to post
2. 2 sender's reward credit for sharing post with C & D.