Oomph-wise, they claim a good 4x over what the Raspberry Pi 4/400 have. Note that rPi's is known to be anemic due to serious memory bandwidth bottlenecks, barely able to keep up with filling a 1080p screen.
Currently they do not support the specific variant used in JH7110, but they seem to both be variants of the same architecture.
JH7110 has the BXE-4-32MC1[0], whereas the driver currently supports the BXS-4-64-MC1[1].
No idea about compute, and AIUI openCL suport in mesa3d is still a disaster for all drivers.
Yes, and they've been around for a while. If you're old enough, you might remember the name "PowerVR".
Today, they mostly license GPU designs to SoC vendors. You'll find their designs in e.g. Android phones.
Notably, JH7110 (RISC-V SoC used in VisionFive2 and Star64) uses one of their recent GPUs.