Given the distance you're covering, I think you'll get a good value out of the Eurail Select pass. The 3-country version now allows both adults and youths to choose second class, in which case a pass for 6 travel days in Benelux-France-Switzerland would cost $381 per adult on the group rate and $365 per youth. This would also give you some discounts on lake boats or mountain lifts in Switzerland (without counting as a travel day). Or compare to 4 travel days on the 2-country pass for Benelux-France at $281 per adult and $269 per youth.
Sam has already indicated which legs on your route need reservations, but for further confirmation and detail, the Deutsche Bahn train schedule link at Looking Up Train Schedules and Routes Online is the best resource. When you expand the schedule results to "View Details," you'd be looking for the phrase, "Subject to compulsory reservation."
Next step would be to only request reservations for those specific portions of the route, which you can do at the same time that you buy the pass. You can also book them later, but some might require delivery rather than print at home or pick up in station options..
Domestic TGV reservations cost $12-27 per person, depending how full the train gets, and this is also the price range to Strasbourg; these trains no longer place artificial limits on pass travelers but they can fill up. Thalys reservations are about $25 in 2nd class and do limit the number of pass holders. Reservations directly from Paris to Basel can be more expensive and limited; see https://www.ricksteves.com/travel-tips/transportation/trains/france-rail-passes.
If the strike were to be continued in July following the same pattern that it has been, then July 11 could be a strike day, with some portion of French trains cancelled. A pass would allow you to get on any train still running in any direction (but with no guarantee of seats). The best new schedule might be earlier or later than your original plan.
If buying regular tickets, the reservation is automatically included when required, but you may still need to break down a multi-connection route into parts (e.g., just one or two connections per ticket) to be able to buy them. During a strike, a point-to-point ticket would be good for any train on the planned route.