Personal context: I am American, have lived in 9 countries on 5 continents & currently live in Europe, and am the same age as the OP.
Immersing oneself within another culture is almost always worth it, but like anything valuable there are always challenges. Psychologically, the Gartner hype cycle will apply to you and your family (replace “innovation trigger” with “new culture trigger”). Given your visa situation is unknown, what’s your backup plan if you can’t work? (e.g., go back to university, learn a new language, etc.) I can’t stress enough to have a plan here. Having one partner being productive in a new culture while the other is mired in the “trough of disillusionment” for a long time is a recipe for immense family/financial strife.
A good starting point for financial questions you might ask yourself:
• Will your children go to private ($$$$) or public schools?
• Will your partner’s employer pay for tax preparation and for how long? Finding international tax people, let alone competent ones, in the USA is extremely difficult & $$$$. Do not underestimate how Byzantine/inane/amoral the US tax system is.
• How are you handling international banking & investments? (Goes with the tax part above)
• How are you handling private pension contributions? (Goes with the tax part above; *warning*: different governments may not recognize foreign pensions and instead treat them as taxable investment accounts…. Tread *very* carefully here.)
• How are public social taxes handled between DE & the USA? (e.g., US $$$ into Social Security is credited as DE €€€? Or just time credits to qualify for a DE pubic pension? Where will you retire, the USA or DE?)
• Are there any social taxes that need to still be paid in DE while you are in the USA in order to use healthcare, education, etc.? (for your return, in case your partner looses her job, kids want to go to DE university, etc.)
• How will you establish credit? Remember, you are starting with no credit history so large purchases (car, etc.) will be difficult. Especially in the USA where credit is the norm.
• Will you rent or buy a home? Can you qualify for a mortgage and if so, when?
• How can you obtain a US drivers license? (e.g., Can your DE one be instantly swapped for a NJ one? Or will you have to take a drivers test? If so, does that require you pay for drivers school? Does your new license have restrictions on car types that you can drive and for how long?)
• Is your partner’s company paying for shipping of your furniture, etc.? Or will you buy everything new? What about electronics that need to be replaced? (e.g., vacuum cleaners, kettles, etc.)
• What is the best visa for you & your partner? *warning*: Do some research or pay for independent legal counsel here. Remember that the types of visas that your partner’s company will suggest/initially sponsor may be in their best interests and not yours. Can you qualify for a visa independent of your spouse? (i.e., so that your whole family isn’t 100% dependent on your partner being at her current employer.) Are there any preferential visas available to you via DE/USA treaties? (E.g., E1/E2, etc.) This area can be really expensive to fix afterwards, so make sure you get what’s best for you.
• Is your partner’s company paying for “home visits”? (e.g., return flights to DE 2x a year, etc.) If so, for how long?
The above is just a starting point, but I’m sure the “global mobility industry” has others to be found.