A bridge locks the native token into a contract on the source chain and mints a "synthetic" or "wrapped" token on the destination chain.
A swap is the exchange of one token for another.
A cross-chain swap is the exchange of one token on one blockchain to another token from another blockchain.
Squid is not a bridge, Squid uses Axelar's bridge and generalised message passing to enable swaps and token transfers across chains.
Squid charges no fees, and does not take margin on gas.
Yes, by Ackee Blockchain and Consensys Diligence.
We are DEX agnostic, but will be usually using Curve for the stable swaps, and major DEXs on each chain for the native token swaps, including Uniswap, Pangolin and Stellaswap.