Hi Chettyrk - Welcome to theforum.
Sounds like a great opportunity.
Spring weather may be rainy ( or not), and April will be between seasons in the high Alps.
To help better understand possibilities, where is your departure flight on the 26th leaving from?
Also- 4 star hotels are usually worth the money, if you use the facilities, but I tend to use 3 star hotels, or even 2 star..
In Switzerland, 3 stars get you clean, well managed and comfortable hotels, but lacking some of the facilities, such as a swimming pool, that you get in 4 star.
Stars are assigned by the SHA, Swiss Hoteliers Association, and have strictly defined characteristics needed to reach each rating. If you use star ratings from on-line services, they are an undefined set of standards. Often merely a consensus from users who do not have consistent standards.
The forum moderators, Arno and Annika can help with various train fare discounts.
To offer the best advice, they need to know your travel plans, day by day.
Some passes pay for (almost ) everything, at a discount, but are not worth paying for if you don't travel very much. There are a lot of other options, too.
When in Basel, view the Tinguely water sculpture. Not to be missed.