Under the bilateral agreements with the EU (currently still in force, possibly not for long), you do have the right to move to Switzerland for a short time to look for work. What you need for that is a “livret L” as you can't get a “livret B” before you have a specific job offer. I am not entirely sure how it works in practice but my understanding is that you should be able to apply for it at the contrôle de l'habitant.
The official sites from the federal authorities do not advertise this possibility but here is a document from the city of Lausanne that describes it in some detail (p. 11):
Autorisation de courte durée (livret L CE/AELE): La durée de validité de cette autorisation est déterminée par celle du contrat de travail. L’autorisation de courte durée peut être établie pour une durée totale de 12 mois au plus et est accordée aux personnes qui disposent d’un contrat de travail d’une durée de moins d’un an. Les personnes en recherche
d’emploi obtiennent également un livret L CE/AELE après 3 mois. L’autorisation peut être
renouvelée après un séjour d'un an au total, sans que le titulaire soit tenu d'interrompre
son séjour en Suisse. Le titulaire est libre de changer de domicile et de lieu de travail.
Personally, I would not open a bank account or worry about taxes and the like before getting a job. You have 12 months to apply for an exchange of your driver's license so you can also wait to see if your plan works out before doing that. Same thing if you wanted to import your car (note that to benefit from a duty and VAT exemption, you must have used the car for six months before moving, you can't buy a car in France now and hope to import it as part of your personal effects). You have to decide for yourself if getting a car immediately is necessary but the public transport network is extremely good in Switzerland, if expensive (I would say better than France and many other European countries) so it seems entirely possible to live without one for a few months.
Customs formalities for your personal things are a bit more tricky. You do have the right to import personal effects free of duty under some conditions but it requires some paperwork (details on the customs' website and ch.ch). The biggest issue for you will be proving that you are indeed moving to Switzerland. A work permit is explicitly not required but you do have to provide some other proof. Without a rental contract (or would your friend be prepared to provide one?) or work contract, you don't have much to go by.
The border is not intensively patrolled so if you just have a few things in your car (as opposed to a lorry full of expensive stuff), you might be able to simply carry them over and get away with it (done it before – and I was only transiting – when I was young and foolish!). But it is somewhat risky, a control is always possible and you would presumably be liable for a fine if found out. Another solution would be to find some place to store your things and fetch them once you have a job offer.