Absolutely! Here are my travel tips for you:

Best Time to Visit:
The best time to visit these coastal cities in South Africa would be during its summer i.e., November to April, when you can explore the beaches and indulge in water sports.

Route and Accessibility:
All these cities are well connected by road and flights. The drive from Port Elizabeth to East London takes approx 3 hours, and a further 6-7 hour drive to Durban. Considering the distance, it's advisable to plan night stops. Alternately, a good network of domestic flights can speed up the process.

Altitude and Acclimatization:
These are coastal cities at low altitudes so altitude illness isn't a concern. However, be prepared for hot summers.

Accommodation and Booking:
There are various accommodations available, from luxury hotels to budget-friendly guesthouses. It's advisable to book at least a month in advance to secure a good deal and avoid any last-minute hassles.

Clothing and Essentials:
Pack light summer clothing, a hat, sunscreen, and sunglasses for daytime, with a light jacket for cooler evenings. Don’t forget a swimsuit for the beaches and water parks.

Health and Safety:
South Africa has a relatively high crime rate, especially in bigger cities, so it's always good to be cautious about personal belongings. Stick to crowded areas and avoid isolated areas, particularly at night. Use reputed taxi services or hire cars from recognized companies for traveling.

Local Etiquette and Respect:
South Africans appreciate politeness. Remember to say "please" and "thank you". As South Africa is a multicultural country, respecting local customs and traditions is appreciated. If you're visiting religious sites, dress appropriately and follow the guidelines. Avoid discussions around politics and cultural sensitive issues.