This may well be mumbo jumbo, it is certainly speculation, but there does seem to be a logical link to your speculation.
Universe = that which we observe, or can assume to exist as a logical extension of what we can observe.
Cosmos = everything that exists, or can exist.
I use the term “cosmos” to avoid any complication that might arise from saying that the Universe is both finite and infinite.
The Universe is finite; you have produced considerable evidence of this. Possibly its apparent finiteness could be a function of our limited ability to see anything beyond our 3+1 dimensions, but that is a side issue.
The cosmos is infinite (this includes eternal). In eternity there is no passage of time. The apparent passage of time is a feature of our restricted dimensionality.
In the dimensionality of the cosmos, everything that can happen is (happening) now.
Our Universe exists because it is eternally borrowing and repaying energy from/to the cosmos. In the frame of reference of the cosmos this is static, but we experience it as happening in linear time because we cannot see the whole picture.