satellite. i think it was 100mins for free and u will get your own german number. but u need an adresse in germany (not necessary to prove that if i remember right).
i got a recommendation for a paid version. callcentric. haven't used it yet as ibstill have credit on skype. but should be similar to Skype and cheaper
i am not interested in a us plan. i want international calls. and i am already using a different app for my calls which is way cheaper
and also the person asking in this group was asking for a possibility to call the us gov. most probably he wont need a monthly plan for a few calls to the us..
i guess no one will be able to answer your question as it depends on many factors. in general i would say no need to worry. there people with way more entries every year without a problem.
both is possible. there is always no guarantee if u do a border run that they will let u in. but rarely happens and mostly to people who did this way more pften than u did