I was running a PMax campaign and it did well over the time but now, it is not performing and I am facing high diminishing returns. So, I have heard from an expert if I just remove the conversion goal and change my Maximize Conversion Value stategy to manual cpc I can get some extra ordinary results. What is your thoughts on this...

I wonder what kind of situation that's suitable to use the shared budget strategy.

I have over 1000 skus. Should I segment them separately with item id or just make it a total listing group? What's the pros and cons of them? Running a campaign with one listing group or with several ones is better or not for getting good performance?

Google limits the number of each listing group to 1,000 ids. I wonder how many ids should be added to a new campaign in order to make it work well. We have totally 30,000 item ids in GMC. But only 20% of them have cost. Considering about the limit budge of $300 each day, how can I distribute my budge to each campaign, while at the same time can make goog use of our products?