For Bitcoin, BitPay's Insight API should meet your requirements. Its API methods should work nicely with Google Sheets, e.g. to check an address's balance:
The rate limiter can be disabled if you host it yourself.
Keep in mind that IMPORTDATA is executed remotely, so your API server will need to be publicly available, whereas 192.168.1.101 from your example is part of a private address range.
sounds exactly what I need. Now to get the install issue figured out.