1. Afaik, if an address has a large number of transactions, they are not retrieved. In some rare cases it may be good to "lift" the restriction or at least return the last few and the current balance.
Raising limitations isn't really what I'm looking for, then you'll just have a ton of transactions that you have to data-mine. And paid block explorer APIs can fetch addresses with several transactions without problems.
Electrum protocol is rich enough for regular user. But for advance user, API which return statistic data would be useful. Few example,
1. Average block time within last X blocks (such as 36, 144 or 2016).
2. Total transaction size on mempool.
Yeah this is exactly what I mean. Normal users who just want to send and receive money don't need any of the more advanced queries that power users and businesses could use for building services on top of them.