Should I replace my kitchen GFCI outlet with an AFCI/GFCI combination outlet?
If it's not required by your local code, then I wouldn't bother. If it is required or you want to do it regardless, then I'd get a AFCI/GFCI breaker which will protect all the wiring and outlets on the circuit (not just a single outlet and any downstream wiring & outlets). An AFCI/GFCI outlet or breaker won't do much in the way of lightning protection. If that's a concern, then you should get a surge protector for your main panel (which might be something you'd want an electrician to install).
Not only would I not bother, I would not do it, the benefit of arc fault in the kitchen is so minimal it doesn't justify cost or failure rate.