Most people I know bought server plans for the player max or ram not to avoid the plugin limit. The plugin limit can be easily circumvented by using skripts that you made or found for free on the internet.
The search feature makes a huge difference on the marketplace because it increases the chances of consumers finding desirable products. The two times I dared visit the marketplace, I left in an instant because there was no search feature.
Minehut not being thought of as a joke will bring in more money. Reputation is very important in the business world. Whenever I see minehut mentioned outside of these forums, it is not usually positive. People lamented the lack of basic features such as a live console and custom plugins. Now that these are coming soon or are currently implemented, Minehut should be much more competitive with other hosts including some paid providers.
It is ad but true: the marketplace will definitely be less profitable for certain products such as punishment/anticheat skripts and similar skripts that are similar to existing plugins. However, worlds and server-setups should still maintain the same level of profitability I would think.
You mention server creators picking the cheaper option. I disagree. You treat minehut users and server creators as though they are intelligent beings operating with perfect reasoning. This just isn't true. I doubt they all know where to go and safely get plugin files, how to install the plugins, and how to set up the plugins. Remember that these are the same people who ask what very explicit and obvious error messages mean. Mean while, buying from the marketplace and installing the products is much easier or at least it should be if it isn't (I don't know since I have never bought from the marketplace).
Just some points to consider but I do understand where you come from when you say that the changes will hurt creators of skripts that have similar functionality to existing plugins. However, I think the update should help minehut because none of the features seem particularly expensive to maintain yet significantly boost minehut's utility as a service and product.