Seefeld day tours

Don't know what buses are available. By "we", I'll assume that means 2.

King Ludwig's Castle: 31.60 EUR per person VVT Tages-Ticket. leave Seefeld 9:15, change trains in Garmisch-Partenkirch, then to a bus in Reutte. Gets you to Fuessen at 12:50 with a 50 minute lunch break in Reutte. Then you need to get a bus from Fuessen up to the castle. Return at 17:13 from Fuessen train station Vorplatz getting to Seefeld at 19:56.

Munich: 10.40 EUR per person VVT Tages-Ticket to Mittenwald, then a 2-person Bavaria Ticket for 28 EUR. The Bavaria Ticket must be bought in Germany. You can either buy it at a ticket machine beforehand in Germany (like when you are in Fuessen) or on-line where you can print out a hard copy. Downloading on a smart phone may be an option, but that is over my head. Another option is to go to Mittenwald on the 7:15 train and buy it there. Have some breakfast and walk around Mittenwald, then take the 9:36 train to Munich, getting you there at 11:26. Return at 18:32 getting to Seefeld at 20:45 with a train change in Garmisch-Partenkirchen. If you have your Bavaria Ticket in hand in Seefeld, you can just board the 9:15 train in Seefeld and go straight to Munich. The Bavaria Ticket will cover Mittenwald to Munich and back and include all public transport in Munich for the day. The VVT Tages ticket will cover the round trip between Seefeld and Mittenwald.
The Bavaria Ticket can only be used after 9:00 weekdays, dated for the date of travel, and write the names of all travelers in ink on the back of the ticket. cost is 23 EUR for the first traveler and 5 EUR for each additional traveler up to 5 people.

I have spent considerable time in Seefeld. Day trips from there to Munich and castles when you only have a few days doesn't really make sense to me. I'd pick excursions that are nearer, such as Mittenwald, hiking in the mountains, Innsbruck, Leutasch gorge, etc.