I understand some of your concern, but most of the things mentioned by you are mere speculations. I have been following the news closely and there is no mention from government about keeping any messages/posts in "pending" status. Reviewing any content doesn't mean that it is to be kept in pending status. Also, Sibal has clearly mentioned that the concerned social networking companies are going to do the reviewing and he or Indian govt. don't intend to do it themselves or by Indians.
Also, I too support that technology and IT can do anything. We see new technology and new gadgets doing extra-ordinary things day in and day out. For an IT guy, nothing is "impossible". So, it won't be difficult to pre-screen any photographic or written content. Screening abusive content is the most easy thing to do. In several IT companies, the email content is pre-screened for any abusive,vulgar and confidential information. So, if they can do it so easily, surely, social networking sites too can do it. Even if I go against my belief and agree with you that it would mean more manual work, then, still it should be fine. What is wrong if some people get employment because of this?
Now, for your point about you wishing a friend on facebook and it being kept in pending status. First of all, no one has suggested such a thing. Still, if it happens, you can always wish him/her by sending an email or a message on the social networking site. The best part to wish a friend would be on phone. Atleast, these restrictions (and "pending" message functionality as per your claim) would make today's generation call each other more often rather than rely only on social networking sites for meeting, greeting and wishing each other. This would indirectly help in building strong relations. If any message is so urgent, one should always convey it via phone,sms and email. The only reason being we are not sure when the other person is going to read the message on a social networking site. Also, most corporate offices have these websites blocked. Atleast,if you send an email,they can read your email message.
There are alternative ways to do everything. We just need to look beyond some fixed things. I agree social networking sites give an advantage, but if there is a risk attached to it, I would prefer limiting the advantage and using alternative means on such sites. I can do at least this much for the betterment of younger generation (kids and teenagers) of India.
Thanks & Best Regards,