I believe that many newbies that are coming into crypto today are not all well funded, many can't afford to DCA into any crypto projects, and they are left with a choice to hunt for free tokens through testnet tasks and airdrops, I started this way too and damn, it was a great time to be alive in 2017.
If you are new to crypto and airdrops and testnet are a must for you, please consider a burner wallet, or name it anything you want, e.g spare wallet, trash wallet etc.
This wallet must be use as your shield on the battle field, whenever you plan to join some tasks online, claim tokens or use a new Dex, it's smarter to consider using your burner wallet, whatever will happen happens to the burner wallet.
Someone very close to me got his wallet drained because of an NFT mint, the mistake he made was using his main wallet to do the minting, main wallets are meant to stay offline, even if you have to sell your coins in your main wallet I recommend moving some part into a burner wallet first and use the burner wallet to connect to the likes of PancakeSwap and Uniswap, today we have so many Dexes, just to be safe its better to go this route.
Let your burner wallet do the trades, the mint, and the free claims for you, this simply keeps you a step away from losing the digital assets in your main wallet.
I agree with your thread OP you have made a good awareness to those that are doing the testnet task, it is wise to have burner wallet for your testnet task and have a real wallet for your asset storage or trading. A crypto enthusiast cannot have just one wallet, that’s not possible because they will always be a need to open a new wallet may be due do accessibility and usage. Every one with their choice of preference, some people have multiple account just for different purposes. So people make that mistake just like the OP mention, you will end up losing your money, you won’t be able to keep track of your trades or the activities in the wallet. The wallet will be over bugged and if you are unlucky to fall into a scam From one of the airdrops and testnet jobs. There’s no doubt some of these new project are Ponzi scheme unfortunately for you jump into their hands. This is why in this coming bull run everyone should be careful with the links they click. Because you might just be falling into your reapers hands.
Once you begin your crypto journey, make sure you know the nooks and crannies in the crypto space, and to do that you have to broaden your knowledge about the crypto space, if you are doing the testnet know it very well, and if you are trading know the concept of trading so that you don’t lose your money. Newbies don’t worry it’s not quantum physics, you can’t learn it all in one day, you will learn as time goes by when you show the interest for it.