It is negotiable based on many factors. I used to trade a lot of options and was able to negotiate a reduced rate. Now I trade less than a dozen times a month but still at a somewhat reduced rate. Call your Schwab account handler.
I think am paying about 66cents for stock options and approximately twice that for index options, per leg.
Marginable securities can also be used to absorb the exposure on naked short options. If you have sufficient equity in things like stocks and ETFs, I don't think you need cash to write a naked short call or put. As you get close to expiration, if the option is in the money, then Schwab's algorithm is also going to evaluate whether you have enough equity to take a margin loan that is sufficient to handle the assignment. In other words, if you are naked short a call, there is a specific margin requirement for that call. But as you approach expiration, if it is in the money or very close, the broker also wants to be sure that you can support a short stock position. Same goes for a naked short put. If it is in the money, then it's not just the margin requirement for the put option. You also have to look at whether you have sufficient assets in the account to take a margin loan to actually buy the stock if you get assigned. But you don't need cash just to sell the option.
Yes, I could sell naked if I have enough equity in the account but they told me: If I don't have the 10% cash in my account, they will charge margin interest on the 10% they "loaned to me"?
You may have negotiated a lower rate, or qualified for a lower rate based on your volume. The standard option commission at Schwab is 65 cents per contract, and there is an exchange fee of one cent, so the total comes to 66 cents per contract. As noted by someone else in this thread, there are higher fees associated with certain index options, e.g., SPX and VIX, among others. You can see the standard fee schedule here: https://www.schwab.com/pricing
You can negotiate that down. I would recommend tradier's pro plus plan. $35/month and free eq-options. Very good rates for futures under that plan as well. The front end is a little slow, but worth the trade-off. https://tradier.com/individuals/pricing
Not a lot, but the rate is unbeatable, esp on index vol. I don't like the front end but it's the only app that allows all forms of COB-orders. The app is really laggy, however. Run it on a fast machine. I had to borrow my kids dual 4090 rig to run it.