What is the maximum number of transactions per seconds on Bitcoin Cash? I know that on Bitcoin (BTC) is was 7 tx/s.
The throughput in Bitcoin is not defined in transactions per second, rather indirectly, via block size limit. What matters in the size of transactions in bytes. The more complex the transaction is (complex meaning more inputs and outputs, long scripts), the more space it takes. A typical full (nearly 1 MB) block in Bitcoin includes around 2000 transactions, or around 3 tx / sec at 10 min / block. 7 tx / sec in the absolute maximum, calculated in the assumption that a transaction contains one input and one output (most real-world transactions contain two outputs -- the second one being the change). BCC increases the block size limit to 8 MB, that means it can handle 8 times more (assuming other things equal).