OP is being set up to fail with invisible rules.
If breakfast is such a huge, cereminious occasion, why bolt off the moment they've finished their communal Mystery Delicacy. Is it really such a hardship to stay longer while OP enjoys something she actually chose to eat.
If they had indicated that they were going to Cafe X and having the Mystery Delicacy because it's quick and fits in before moving on to another destination, that would be different.
Only offering a specific drink and expecting people to go thirsty if they don't want it is just downright mean.
Getting up on the day and being told we're going out at an unspecified "early" and going to get ready as a result is not unreasonable. If OP's routine is more time intensive then they should have pre-warned her with the specific time the night before so that she could accomodate it. It's their lousy communication that caused the issue.
Is their surname Jom Un? Because they're ridiculously controlling as evidenced by taking exception to things like going for a walk between 2-4 that doesn't impact on them.
There is a major DH issue here because he is not helping OP navigate their ridiculous rules and then getting stroppy with OP when she inadvertently breaks them. If they have children, this is likely to be a major issue as he'll default to mummy and daddy first and not the interests of OP and children.
It sounds like a case of excessively controlling parents and enmeshed, enabling children conditioned to conform to parental groupthink.
Do not go on holiday with them again, no doubt that will be wrong too, but you're just too incompatible for it to be fun.
To survive this one, try to dig out as much information about plans, timings and expectations before each stage. (Athough that will probably also be "attention seeking" and piss them off too)