@Signa I think it's up to you. So far it doesn't seem like this is going to get worse, for a couple chapters at least, so if your enjoying it then keep enjoying it. As for me I'm going to kept reading for now, it could make a sudden comeback after all, you never know.
Multiple predictions
1 Old guy is Noriko son (could be possible with how distorted time is in the dungeon)
2 Old guy is Alcatraz being in the dungeon for so long and running constantly he ran to the final floor couldn't run anymore and filled with total despair of being in the dungeon for so long running
3 MC is No life king from another timeline somehow (clothes seem similar and she said he could raise his agi stat here so possibly killing his past self and taking EXP)
4 Old Guy messages are specifically meant for MC and old guy and god are working together or the same person