If you have some questions...
No, you do not need to take the TOEFL but the language of instruction for all the doctoral programs taught within the Faculty of Business and Economics is English. Although you do not need to show proof of your English proficiency at the time of application, English proficiency is necessary to succeed on the program. Although not required, having a basic knowledge of French would be useful for a smoother acculturation in Lausanne.
No, these tests are not required for your application but if you have already taken any of them, you can submit the scores along with the other application documents.
In principle, an MBA is not considered on the same level as a Master of Science degree (or equivalent). Students with an MBA may still apply and your formal eligibility will be determined by the admissions service of the University of Lausanne upon submission of a complete application file (as well as by the Ph.D. admissions committee).
The registration fees amount to CHF 280 for the first semester of enrollment and CHF 80 for each additional semester. In addition, you need to pay an administrative tax of CHF 200 for the review of your file if you are an external applicant (i.e., did your previous studies in a foreign country). As for living expense, we estimated that you will need about CHF 2000 per months to live in Lausanne.
Yes, it is possible but challenging. It is a full time program and one needs to spend about 20 hours per week on the program. Given the course load of the first two years, you should find a job which is flexible in terms of working hours to allow you to attend the classes required for your Ph.D. More information on the doctoral courses here.
The Ph.D. should last no less than 6 semesters and no more than 10 semesters.