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SurveyJS
Open-Source JSON Form Builder to Create Dynamic Forms Right in Your App. With SurveyJS form UI libraries, you can build and style forms in a fully-integrated drag & drop form builder, render them in your JS app, and store form submission data in any backend, inc. PHP, ASP.NET Core, and Node.js.
This website gives excellent advise which 16 validators to select based on various criteria: https://james-sangalli.github.io/dot-validator-selector/
You can use Fearless (https://fearlesswallet.io), PolkaWallet (https://polkawallet.io) or PolkaDot.js. If you use a centralized then use Kraken as they have been supporting Polkadot/Kusama the longest. The recently increased Kusama from 12% to 18% and may do similar with DOT. You will get a higher % if you use the native wallets I listed along with the ability to participate in parachain auctions.