Dexhunter slippage

I’m interested in using DeFi instead of CeFi, so had a brief look at Dexhunter.

The ADA to DJED conversion for 100K ADA has a 6% slippage. This seems pretty high. I assume this means someone is offering their DJED for ADA with a 6% mark up. Is this how it works?

Do people actually sell their ADA for a 6% loss? This seems like a goldmine for DJED sellers! I’d have thought the 6% would be much lower, as DJED sellers fight over the ADA sellers.

Is this 6% slippage likely to lower during a bullrun, due to more liquidity being offered?

If USDC is enabled on Cardano, would USDC likely have a much better slippage?