If it worked like you're suggesting I wouldn't criticise, but I don't believe it does. The drift, weight and limit are arbitrary limitations because they don't know how to work within the framework of the physics bound world they've created. Nothing worst than boosting into that odd wall called the speed limit. It doesn't feel like you are boosting to a top speed. It just feels like running into a wall. Anyway, I respect your point of view even if I don't quite see it the same. All I know is they aren't likely to come through on their promises because there are too many technical hurdles ahead of them and even simple ones like dealing with IM seems beyond them. They're going from the frame point of cinematic and artsy first, gritty and bound by physical rules second and the two don't mesh. It's backwards. I have come to the honest conclusion that it will be a massive flop. I am now trying my damnedest to jump ship. Good luck to them, I want out and I've messaged them as much. Hopefully I can be one of the two and a half + thousand who were allowed to escape their clutches. Anyway, I don't mean to get all into that here. Perhaps I should just let it be (publicly). See you around Troels. I value your input.
I don't think mass is set as an arbitrary number, at least looking at some of the numbers, they seem way too specific and accurate to have been arbitrarily picked by someone (for instance the new Esperia Glaive has a mass of 29,387.15 kg), I would guess that the mass is calculated based on the volume of the actual 3D model following some sort of defined rules. Some of the older ships and the ones still in the concept phase have numbers that are far too clean to have been determined based on the model, but I would think those numbers are just placeholders until the final model is done (for instance the Reclaimer is set to exactly 600,000.00 kg).
Drift and and speed limits are however arguably arbitrary, but they still work within the framework of the physics bound world. In other words, the physics model, and the setup of the ship allows you to move with a certain level of drift and acceleration if there were no limitations, but this is then limited down to what we have in AC by the IFCS. The reasons behind these lower limits (relative to what the ship is actually capable of) are plentiful, some of them sensible and realistic some of them less so, and they have all been debated to death on the SC forums. Some of these reasons include: G-forces, structural integrity, simulating WW2-like dogfighting, simulating the response time of atmospheric flight, simulating the response times of an FPS (which is of course the exact opposite of the previous one), Lore reasons, rule of cool and so on.
And yes boosting into the speed limit can feel a bit odd, but for what it's worth there has been talk about changing how the speed limit works (
dev link).
With regards to them coming through on their promises, I really couldn't tell you, mainly because (as I've mentioned before in this thread), I'm not terribly certain exactly what their promises are. All I really know are broad strokes and vague goals.
Btw. if you want out, you might be better off looking at the gray market, since some packages/ships are worth more there than their original price (which I assume is all you would get back from a refund).