Questions on: bip66

From BIP66: The new rules are in effect for every block (at height H) with nVersion = 3 and at least 750 out of 1000 blocks preceding it (with heights H-1000. . H-1) also have nVersion = 3
While transactions are signed, the signature does not currently cover all the data in a transaction that is hashed to create the transaction hash. Thus, while uncommon, it is possible for a node on the network to change a transaction you send in such
However, it was found later that even BIP62 had its own set of flaws that might conceive some more troubles for the Bitcoin network. Back in 2013, some scholars from University of Warsaw also proposed a separate modification of Bitcoin, where modifie