hey,
not sure if i can help you with any work/age-related issues, but i can tell you a bit about TUM and that master, since i finished the equivalent bachelors programme at TUM this spring and have many friends who are currently doing the master.
you should find all the information on the programme requirements as well as on the application process on the programme website. they also publish the ranking algorithm for applicants, you can check if you have good chances. a GMAT >600 for example gives you 10 points in their system.
as you probably know, you need to fulfill quite a few extras in addition to having a bachelor. you need to have >10 credits in economics and >15 in maths/engineering. furthermore you need proof of english proficiency. that's not all, but i suggest you check out the link and/or contact them - TUM employees usually reply in a few days!
how do i best describe the programme? honestly, i think it is very underrated. it currently scores ~25th place in global masters in management rankings, but you have several advantages. first of all, it is almost free of charge. secondly, you are at a major technical university and can actually do courses in programming/electrical engineering/mechanical engineering/etc. at world-class faculties. you will therefore always have a quantitative edge over those who did pure business masters. last but not least, munich is one of the best cities globally in terms of quality of life and ranks 2nd as student city globally.
TUM itself is quite a demanding university. the teaching is quite good, but it could be better at times, especially since some exams tend to be really hard (60-70% or more fail). but these are mainly the technical subjects, which you can reduce to a minimum in your master, if you want to (in bachelor some are obligatory). all in all, it is manageable to score high grades if you put in the work. the university is generally very well organised (also in terms of online lectures etc.) and has pretty good facilities.
the programme itself is highly popular in germany, since it is one of the best national business masters. generally, you have a lot of flexibility in choosing your courses, which means that you could do a mix of 40% finance, 40% economics and 20% mechanical engineering. or you could do 60% strategy and 10% informatics/supply chain management/maths/renewable resources... the wealth of courses on offer is overwhelming and this is a huge plus. you can basically "build" your master so to suit your own interests and abilities.
TUM itself is consistently ranked as the best or second best university in germany. globally, it ranks between 20-50, depending on the subject. the TUM school of management is one of about 100 business schools in the world to have a "triple crown".
honestly, i feel like there is still space for improvement and like TUM school of management is on the rise. it is certainly a very good degree to have, if you plan to work in germany afterwards. you should prepare for diving back into some advanced math, but i'm sure you will cope (you can avoid notoriously hard courses by not picking them). the programme is quite rewarding and you honestly feel like you can bring the best of both worlds together.
hit me up, if you have any questions
best
daniel