IF you don't set limit to cpu & memory, your pod QoS will be burstable and from kernel/cgroup perspective this process can be killed - it's only question of oom_score_adj.
But there are serious drawbacks if you don't set requests/limits for mission-critical process, is that they can be killed by kernel to free some resources (if the node reach max resource usage)
When you don't set cpu/memory limit your pod QoS class is burstable, which better then BestEffort, but still get assigned `oom_score_adj` score. IMHO you almost 99% you want `Guaranteed` for critical process.
Does Kubegres works with any TCP proxy, and if does - is there any recommendations which one?
Running ingress via Load Balancer is quite costly option in cloud context. At the moment is seems that nodeport is only realistic alternative.
What I'm trying to say that while try to avoid one pitfall you fall right into an other - in short there are good reasons to use cpu limits.