Ethereum is a coin. It has an own blockchain. If any token created on ethereum blockchain, they are ethereum based tokens. Ethereum based tokens mean ERC20 tokens.
I think people will move to decentralized exchanges in the future. Because the decentralized exchanges private key owned by the user, users can trade any amount without any KYC verifications etc.
Sounds like you are going to be a bounty manager. You can post ANN threads in official Service Announcements (Altcoins) section and bounty threads in official Bounties (Altcoins). There are too many ANN and bounty threads in those sections. You can get an idea from looking at those threads.
If you put one signature in your bitcointalk account, Don't you have any extra space to put another signature to your bitcointalk account. Because signature spaces are limited rank by rank. You can put another signature after the one campaign.
In these days buying is the best way to get bitcoin. You can exchange your fiat to bitcoin. There are too many sites to get bitcoin from fiat. Coinbase and Cex are good sites to get bitcoin from fiat.
There too many scammers in this crypto world. Then beginners need to learn more about crypto before invest and trading. My personal opinion is don't give your private keys, login details and KYC documents without doing any research about wallets, exchanges or ICOs.