I've been involved with GCam since 2017 (created one of the first threads on XDA, links above are from my site, work with some modders testing apks, etc). So far, no GCam from the main modders has been found to do that, but it's a fair concern as these apps aren't from the Play Store and modders could add malware/spyware if they wanted to.
To minimize the risk, I we can use versions from well known modders/developers like Arnova8G2, cstark, BSG, Urnyx05, and San1ty (assuming they work on your phone). Also not 100% safe (not even the Play Store is), but I guess it's safer as they keep an eye on each other's work. If someone adds malware, someone else would detect it.
Android phones also have Google Play Protect (https://www.android.com/play-protect/) which scans our apps regularly. It should be able to detect known malware.
In any case, it's something that only you can decide if it's worth using. I never had problems, but the risk is there.
I do not know of any gcam mod that allows that, but depending on your device McPro24fps has support for 10, 15, 24 fps etc.
If you can save RAW/DNG files with the stock camera, you might be able to use DNG Processor to covert from DNG to JPG and bypass some of the bad stock processing.
This doesn't help with HDR/dynamic range, but sometimes photos look better. It should work in the background and start converting as soon you take a picture.
Ive been using this app https://play.google.com/store/apps/details?id=com.gcamdownloader it doesn't list the Moto One Fusion+, i just selected Motorola One Power.
Working fine so far.
ZGCam is the best for Exynos, so if it's buggy, then other versions will only be worse.
My suggestion would be to use GCam for the things it does well and the stock camera app for everything else. Is this acceptable? Only you know. On my Asus Zenfone 6 (Snapdragon), I use GCam for everything but video (slow motion is bad and video is ~90% of the stock quality). It's a compromise.
Some people like to save raw/dng files (I assume you can do that with your stock camera app) and then edit them. Extra work, so it's not for everyone, but I guess you can minimise some of the bad processing from stock JPGs. You can also use something like DNG Processor ( https://play.google.com/store/apps/details?id=amirz.dngprocessor&hl=en_US ) to automatically process DNGs. JPGs usually are more detailed, but it may require some tinkering to get colours right.
Anyway, about Google Camera, they make it for Google phones, which use Snapdragon processors and Sony camera sensors. Some of the Google Camera features use hardware features of both the sensor and SoC, so other hardware will always have limitations.
It's not useful now, but when buying your next phone and if GCam, custom ROMs, etc, are important to you, pick a phone from a "dev friendly" brand (OnePlus, Google, Xiaomi, Asus, etc).