No, Aurora Store does not install Google Play Services. I have used LineageOS a few years ago and back then you needed to install them when you first installed the OS, before even booting into it.
I watched SomeOrdinaryGamers for a few years and it became quite uninteresting near the end of that period. I stopped completely when he told his audience not to buy Nintendo Switch 2 and went ahead and bought it shortly after. That guy is not honest or genuine.
If you have to choose between one, then yes; full disk encryption is superior. But they should ideally be used in tandem.
Without secure boot, you are vulnerable to evil maid attacks. A bad actor can modify your bootloader (which has to remain unencrypted) in a way that allows them to steal your encryption keys. Secure Boot prevents running unsigned bootloaders, which negates this risk.
DXVK was the last (IMO) major key in enabling proper Linux gaming.
Here's a short interview with the creator of DXVK.
Prior to this Wine was able to run some simple Windows applications, but games (which heavily rely on GPU acceleration) lagged quite a bit behind since DirectX is a Windows exclusive graphics API. Instead, on Linux we have Vulkan which is similarly feature rich, but an open standard. DXVK translates DirectX API calls to Vulkan, which GPUs on Linux can understand, similar to how Wine translates Windows syscalls to the Linux alternatives. Even though Wine existed for a long time, DXVK's development started quite a bit later.
No, Aurora Store does not install Google Play Services. I have used LineageOS a few years ago and back then you needed to install them when you first installed the OS, before even booting into it.