Sure you can leave the bot running for a long time. We have several members already running the arbitrage bot for months. This bot is designed to be used in the long term instead of short term. It is because its low risk advantage , and also slow but steady profit will yields better profit in the long run.
If you often open and close bot in the short term, you will have to pay more fee which will reduce your overall profits. It is advisable to run the bot for the long run instead of short term run.