Lots of thoughts here, but I'll try to not write a book!
Clubless can be fun to play, but there are most certainly downsides, for instance:
I would say straight flush (SF) in spades or hearts is very tricky, and therefore easy to make "not good". Unlike most clubs, when you play your dudes or goods, you're often lessening the strength of your draw structure as they remain on the board. If you have 4 of each hearts in 6 though K, for instance, if you play out 2-3 of your 10 of hearts, your chance for a SF goes waaaay down. These decks can do much better with regular flushes, but the SF can be very tricky, and thats often where cards like Decimator Array come in to help.
If we're talking clubless gadgets, cheatin punishment is a problem. In your first post,
I think slipping in a couple of club cheatin resolutions is a good idea, and unless your tolerance for risk is extremely low, one testing range would probably be enough. Unless you are playing Lacy, you can keep those clubs in your hand whenever you see them, and you can see whats in your discard, and generally be pretty safe. Ricochet is also another great option for one or two of as surprise cheatin res.
The best part is if your opponent sees one of those cheatin res in lowball or discard, they will be scared of cheating even if they know you are almost entirely clubless and have nothing on the board. (A wise opponent may simply try to "cheat through the pain" though and draw out what's in your hand if they know you are very limited on cheatin' res)
From the compendium/faq: "His ability cannot raise his bullet rating above 5, even if he has bonuses from other
sources such as Weapons."
One last no club gadget option that I didn't see posted yet is an entirely draw-structure-less (no draw structure, cannot win shootouts via traditional poker hands) one. You can either go a pure slide method, where you just try to overwhelm them with control points, or one that utilizes cards like asyncoil and force field, optionally with harrowed dudes so that you take no actual casualties, such as this one that I took the latest Gencon Marshal event with: https://dtdb.co/en/decklist/3397/asyncronized-swimming-1st-place-2021-gencon-marshal
No draw structure whatsoever, but can still "win" shootouts via asyncoil gun and/or forcefield + sidekicks or harrowed dudes. Part of the beauty of this game, there are many ways to "win" shootouts without pulling a high poker hand from your deck!