Was the Boeing 2707 design flawed?
The three competing supersonic designs are discussed in this video – The Forgotten American Concordes. Two competing designs from the USA were proposed to the US government, which was going to fund 75% of the development cost: one from Lockheed, and the B2707 from Boeing which was the winning design.

The B2707 was meant to be bigger and faster than Concorde, and this was one of the three issues that eventually saw the project being cancelled:


Concorde flew at Mach 2, heating up the nose to 127 °C and the wing leading edges to 100 °C. The whole plane was considerably longer at cruise than it was on the runway due to heating up from the supersonic flow, but at this speed aluminium could still be used as the main construction material for most of aeroplane. The B2707 would be heating up much more, ruling out aluminium and having to use titanium, skyrocketing the construction price per aeroplane.
The oil crisis of the early 70s raised fuel prices a lot, with unfavourable consequences for the operating costs. It was thought that since the travel time is shorter there could be more daily flights, but:
protests about supersonic booms prohibited supersonic flights over most land, meaning that the only viable market was the US east coast to the European west coast.



  If so, what was the problem with the design? By problems, I don't mean it being financially feasible or sustainable, I mean technical limitations and restrictions imposed by physics. Could this sort of aircraft ever have achieved a sustained mach 2.7, and carry 277 passengers?


Image source

It might have, there were military aeroplanes flying at M 2.7 or faster at the time like the XB-70 Valkyrie built out of stainless steel, but the technology was still immature. Passenger transport implies high reliability and long testing times to verify if the safety requirements can be met, and this was a major issue to be crossed out at the time of cancellation.

So the question: "Could this sort of aircraft ever have achieved a sustained mach 2.7" at the required reliability rate was never tested.