Just make giveaways for top 10-15 coins and that's it. Whoever makes on the list and start giveaway threads.
No, because then a list would have to be made. The forum's stance in general is that all alt coins are alt coins. The old established coins like Litecoin, Namecoin, etc are equal in alt coin legitimacy as PumpNDumpCoin that was made 15 minutes ago. The market decides the validity of a coin, not the staff of Bitcointalk.
Actually coinmarketcap.com is doing great job ranking the coins, so making top 15 list will be off Bitcointalk back.