That is a load of crap. By virtue of existing in our universe, they are subject to the same laws of physics that govern us and our technology. That means they cannot be perpetual motion machines who run forever and ever without restocking on fuel, power, ammunition for their weapons and material to make repairs and make husks.
Element zero is not used up as fuel during the reaction/whatever makes it work. Care to try again?
Nowhere has it been stated they CAN adapt Reaper drives OR Reaper cores, which is completely beside the point because at Reaper speeds the journey will take 230 years, which is still way, way, WAY too long.
Your proof that it's impossible? The thanix was reverse engineered. Cronos station is powered by the core of the baby Reaper. Lore would seem to indicate the opposite of what you want to claim.
And "flying on a burst schedule"? Do I understand you correctly that what you actually mean with this is that they will stop now and then and generate more power over a few centuries, then continuing? If so, you do understand that this will only increase the power draw from the cryopods, completely negating any benefit to stopping in the first place?
Hardly, if it's all automated. I didn't suggest waking the crew at any point.
The people who has to increase the ship's size to accomodate for another millenium of consumables would care. Time is definitely not irrelevant. If anything, time is THE most relevant factor. Time is what causes the resource requirements to balloon to impossible levels. The only way to reduce time is to increase efficiency, and that requires, ironically, centuries if not millennias of innovation.
If they're in cryo the whole time, the resources are nowhere near as exorbitant as you claim.
There is one other possibility- there are no people going at all. Just fertiziled embryos, or DNA sequences allowing for the regrowth and population of species. I think it's unlikely they'll go this route, but this would cut down on supplies even more.
Which brings me to the "Wait Equation" - there is no point in building an enormous, resource-hogging intergalactic ship many times more expensive than the Crucible that will take 500 years to reach Andromeda when 250 years later a ship only a fraction of the size and many times faster will be produced, catching up to and racing past the first ship.
Source?
And sending the ARKCON colossus during the Reaper War? That implies all the relevant tech was developed in a manner of months (unlike the Crucible, which was based on ancient blueprints millions of years old), that all parts were fabricated and then assembled in a manner of months. Simultaneously with the Reapers systematic destruction of the galaxy's infrastructure and economy. Concurrently with the construction of the Crucible, which was noted for being an astronomical drain of money, materials and personnel.
You. Cannot. Be. Serious.
I assure you I am.
The Ark developed in a matter of months? Not necessarily. It could've started years ago as a pet project that was appropriated and repurposed once the Reaper threat emerged (and I mean before the war. It'd be nice to retcon the Council as less than total idiots). The relevant tech to make it actually feasibile (Reaper drive, core, maybe even Crucible components/theory) were the finishing touches.
It's not a waste of material when you consider the time expense in consumables and the fact that a lot of star systems may be ineligible targets for drive discharge, for example star systems with planets that lack magnetic fields. The size of the planet also determines how long discharging takes, and the size of the ship determines how often it has to discharge. The ARKCON monstrosity would have to stop to discharge as often as a pregnant woman has to stop to go to the bathroom.
This is of course beside the point that discharging tech and better long-range FTL comes really handy when you're charting unknown space in search of relays to unlock, thereby enabling faster travel across the galaxy. You know, what Mass Effect: Andromeda could have been about if it was called Mass Effect: Milky Way instead.
You continue to ignore potential innovation in that area. The rest of your point would apply if the pre-Reaper war galaxy was interested in exploring and advancing beyond the relay network. Clearly they were not. Or at least it wasn't the mainstream school of thought. The relays were convenient and numerous enough, as were the discharge points. The point remains, the fact that no one bothered to invent alternatives that saw widespread use does not mean they couldn't or that someone didn't, in relative isolation.
Even with any of those parts, the Reaper tech is so advanced in comparison that it's not like Earth is going to just say hey, lets reverse engineer this because we can? None of the races even understood anything about the technology of the gates, which strongly suggests they would know jack about dissecting Reaper tech. And even if they could, how many years do you think it would take them to reverse engineer such advanced tech? Then they still need the time to add it into the design of the Ark and adjust for that.
Cerberus had to allow themselves to get indoctrinated among a host of atrocities to even learn from Reaper partners that were partially willing.
So no, the Ark would still not have Reaper tech if it was to leave anytime before the trilogy.
Turians managed to reverse engineer the thanix just fine. Despite pretty much everyone in the series being complacent morons, you underestimate human ingenuity.