How does EOS handle the long term blockchain size? with thousands of transactions faster than bitcoin wouldn't the blockchain become too large to manage
Bitcoin supports validation of transactions assuming all nodes have access to the full history of block headers which amounts to 4MB of block headers per year. At 10 transactions per second, a valid proof requires about 512 bytes. This works well for a blockchain with a 10 minute block interval, but is no longer "light" for blockchains with a 0.5 second block interval.
So that EOS implemented Merkle Proofs for Light Client Validation (LCV) which you can check out here.
It allows EOS can track all block headers (420 MB/year) will keep proof sizes small.
As computer technology advances we'll see BP's trying to earn votes by offering faster hardware.
Should that not be fast enough.. from the white paper.
"With support for Context Free Actions, scalability techniques such as Sharding, Raiden, Plasma, State Channels, and others become much more parallelizable and practical. This development enables efficient inter-blockchain communication and potentially unlimited scalability."
To put it simply, we can create multiple EOSIO blockchains and have them talk to each other which offers vast amounts of scalability potential.