Point of clarification which will help to elicit appropriate responses from posters. You state budget $8000 flight included. Is this for flights say from Joburg - Botswana return and local return flights from Maun to the Delta. I assume it is not including flights from US & return. Budget total minus flight costs would be useful.
Note that the Devil's Pool usually only opens around the end of August, the exact date depends on the water levels. So with your dates, it's possible it might not be open, certainly if you go to the falls first. If you put the falls as your last stop, I'd say you have a decent chance of it being open but it's not guaranteed. So I'd suggest starting in Maun and ending in Livingstone/Victoria Falls.
If you want a couple of nights at the falls, that leaves 8 nights of safari. August is peak season so pretty pricey in the fly in camps, but you could do a private mobile (which can be fairly luxury camping) from Maun into Moremi and Khwai and then fly from Xakanaka airstrip to Chobe and stay a couple of nights at a lodge there, or there are houseboat options which I have heard great things about but never tried myself. Then get a road transfer to Livingstone. Devil's Pool is on the Zambian side of the falls so it probably makes more sense to stay that side.
I'd guess that could be done within your budget even if flights from Johannesburg are included. I mainly travel on my own so I'm not that familiar with exact costs of private mobiles- not very cost effective for one person but you have a group of 5 so I imagine it would work out quite reasonable.
Devils pool is opening second week of July. With your budget your can successfully do all the good tours and activities in Victoria falls and bots.
Include local flights from JNB only. I won’t dare to think of including international flight.
Botswana is an expensive destination. Noting your budget includes local flights possibly Joburg to Maun or Kasane, Botswana, your budget is probably limited to mid range choices to cover the 11 days you have allotted for the trip. .
Without knowing your travel style, it is hard for posters to offer suggestions. However, if you want to save some $$ you could consider doing a private mobile camping safari. We along with another senior couple did a 5 day mobile safari from Kasane to Maun but it can be done in reverse. If you are open to camping or glamping you could do a non participatory safari whereby you have staff to do the driving in your own safari vehicle, all meals/drinks included and you can opt for dome or large meru style tents with private en suite bathroom, as well you can personally choose your route, length and itinerary. The ground staff handle all the housekeeping and cooking. It means being out in wilderness but the great advantage is just that & the chance be in the midst of wandering wildlife. At the mid range level expect to pay $360 -440 USD PPD all inclusive, i.e. meals/drinks.
We used Lelobu Safaris, a local Maun tour operator to arrange the safari. The alternative is to stay in lodges but those out in the wilderness & Delta are expensive, plus you have chosen peak season to visit Botswana. There are some mid range Delta lodges which are an option. For more budget friendly ideas & lodge specials have a look at this link https://www.botswanabudgetsafaris.com/lodges
Thank you for valuable advice.