Re: Weight, its all about the weight!
All the F1 teams are based in Europe. So they freight their stuff by road to the European races - but by air when they go further afield. Which makes things conisderably more expensive of course - and makes weight and size much more of an issue.
I believe they usually arrive at the track on Tuesday or Wednesday and have to be fully up-and-running for Friday and Saturday practice - and then race on Sunday. But in reality many services will need to be working on Thursday as that's when the marketing circus arrives - and entertaining their corporate sponsors' guests is what funds the teams. Then they pack up Sunday and Monday - and on back-to-back race weekends it's off to the next track and do it all again.
Anybody who thinks this is easy hasn't thought about it much.