You have quite a full program, but I think it is doable with the following remarks:

day 4: train to MP and back to Ollantaytambo. You will probably arrive in Ollantaytambo too late to explore the archeological site there and after a full day tour to MP I would just go back to the hotel and relax.

day 5: allow a full day for Cuzco, all sights are pretty close to the Plaza de Armas, you should not miss Sacsayhuaman (you can walk up from the Plaza de Armas). I don't think you need a guide for Cuzco if you have your tour books.

day 6: car rental is no problem, Panamericana is good quality, no problem driving your own car, however, be aware that you have to cross Lima (traffic is "slightly" more chaotic than in the US). According to your schedule this will be late morning, so trafficwise not a big issue. If you drive your own car, get lunch at El Piloto in Canete before Pisco.

day 7: doing Pisco, Ica and Nazca on 1 day to/from Paracas is too much IMO. If you want to take a flight over the Nazca lines, you should reserve at least the day before and be there in the morning. You could maybe cut the last day in Lima and add a day for Nazca. August/September is not really a good time climatewise for Lima.