Our biggest issues were :-
private health insurance - I was pg at the time the offer was made and not all insurers cover it as a pre existing condition, although locally I could have got basic care anyway
schooling - is private english speaking/bilingual education or an international school (following the IB syllabus) an option , especially if you may move on again in a few years time and want continuity, would you have to fund it or use the local system
housing - perhaps a change of living style to apartment living and sharing facilities with others. Location - near other expats or not - and size/cost
integration in terms of language (does the employer fund any tuition for spouses as well as employees) and culture shock , there may be specialist companies who organise courses in the practicalities for newcomers.
As regards your specific questions, you have to detach yourself from UK life and have an open mind. We had to sell our car , and didn't get a great price tbh, but kept the house which we let out and most of our stuff went with us or into storage. it felt odd havign someone else livng among our things and took some of their comments re decor etc a bit personally for a while.
Treat it as an adventure, take advantage of any local opportunites for scenery and sports and try not to get down in front of the kids. There would be ups and downs and ds , who was 3 , had a hard first 6 months but eventually didn't want to leave. Visits from family and friends helped as did emails and letters. Invite people to stay (there will be an initial influx then a lull the longer you stay).
Use Sky if needs be (we survived on BBC prime, CNN and the occasional dual language programme for a year and really appreciated UK tv when we got Sky ! ), but the local cable stations wherever you go may have BBC1 and 2, BBC World et al anyway, so check beforehand. We also used to listen to BBC World Service radio before we got Sky. Use Amazon.uk to get English books, films etc, if you are lucky local VAT will be lower , offsetting much of the shipping costs, or use one of the other Amazon sites which stock English books. You may find locally based internet sites which stock UK or US food stuffs etc , but probably at a premium ! You do eventually adapt your cooking to suit the locally available goods, or ask visitors to bring supplies !
As regards bureaucracy dh and his hr dept did most of the organising, mainly because I had no local language and as a trailing spouse lacked status . He started work a month ahead of our arrival so had organised bank account, car, permits etc before we got there. You tend to pick up the rules as you go long but I was very fortunate to have a fellow Brit (the wife of a work colleague of dh), living in the same apartment block with children the same sort of ages , who was very happy to help and point me towards paediatricians, supermarkets etc.
Sorry it is a bit long but hope this helps !