SYR offers live arrival guarantee at the rate of $2.5 per $100 insured value there are certain criterias. https://www.shipyourreptiles.com/en/...help-insurance
Flat rate is whatever you want to charge knowing that in many cases you will likely absorb some of the cost (gas & packaging will easily add anther $10 to your expenses), also keep in mind that many people are reluctant to pay more than $50 flat rate for shipping even though it will cost you anywhere between $50 to $85 to ship a 12x9x6 box (that's only for the label)
You cannot ship to Hawaii Hawaii has very strict laws that prohibits reptiles from being imported , for Alaska your shipping window is very slim due to weather condition, as for Puerto Rico not sure what laws or process are, realistically your sale will be on the mainland.
When you do ship only do so Monday through Wednesday, you can ship on Thursday but I would recommend that if you do so it's only to a hub, if a home delivery package is delayed when shipped on Thursday it will not be delivered again before the following Monday, if it is delayed when shipped to the hub it will be available when the hub opens the next day. The package can be redirected and halted to be pickup at the hub but not all customer have the means to get to a hub.