This is pretty neat! I work at a crypto exchange that is quite popular for arbitrage across exchanges--we have a single orderbook made up orderbooks from multiple exchanges, and we allow you to trade on all of them with only an account with us. I'll be sure to share this link with the team. :)
they are. Let's say you choose an opportunity of 3-4% margin. Deduct your exchange fees for buying & selling which should be around 0.4-1.0% (depends on your volume etc). Then deduct another fee of 0.5-0.7% for using an online money transfer service. 1-3% profit every few days without doing anything much. Have done it by myself over the last 2 years.
If you use my service you can make DNS changes live with nothing more than "git push", keep a compete history of records, and have TTLs of 60seconds with ease.