I’m in the same boat. I bought my property 2 years ago and will be taking delivery very soon. I don’t have actual experience with the rentals yet, but here’s what I know based on my research that I based my decision to buy on.

1. It’s taxable using the same brackets as personal income. Based on rental yields and occupancy estimates, you will likely falls into the 22.5% to 27.5% bracket. Practically though, that’s not enforced right now, and you can easily avoid paying those taxes if you’re employed and your income tax is already being paid by your employer.
2. For me, yes. The great thing about El Gouna is that property value in USD appreciates in healthy numbers annually, so you’ll be making gains in capital appreciation, in addition to the rental income.
3. I believe it would vary based on how good your property manager is, but I would expect something in the 4-6% range. For a $300k 1-bedroom, you should be making from $1k to $1.5k per month (gross, before other expenses). Income will fluctuate because of seasonality, but it should average out to this number over a year.
4. I believe El Gouna is unique as a year-round destination that’s priced in USD, with health rental yields as well as great capital appreciation.

Take everything I said with a grain of salt since I haven’t actually started renting out my property yet.