We used to think that bigger blocks increase rate of orphaned blocks and hence it's more profitable to put all miners into a single location (i.e. centralize). For blockless blockchain it's not a case because it's allowable to "mine" on top of old transactions.
We already mine on top of old transactions, that's certainly not novel.
To allow full nodes to operate with limited bandwidth, i.e. to allow decentralization.
Yes.
To allow full nodes to operate with limited bandwidth, i.e. to allow decentralization.
DAG makes it much easier to handle intensive data flow because of multicast. A single transaction easily fits into MTU and if it's not received by few of the endpoints it's not a problem. Even more, TPS bursts are automatically smoothed, a full node needs majority of the transactions only if it sends or receives money, in all other cases it needs only to verify PoW and rebroadcast transactions to its neighbors (if multicasting is disabled).
The full node is the heart of the issue. If there are only a handful of full nodes, and thousands of thin clients, then this protocol isn't decentralized, which is the claim in the whitepaper.
DagCoin is a cryptocurrency design that attempts to be highly decentralized by merging the concepts of transactions and blocks and making each user that transact a miner.
Emphasis mine.