You can disable the update checker with a very simple config change.[0]

As for :x being slow, I'm not sure what that might be, it certainly isn't the case for me, it quits instantly. Try asking around in their support channels?

[0]: https://www.lazyvim.org/configuration/lazy.nvim (look for "checker" field)

It sounds like you don't have lazy loading enabled. No way it should take that long to start up, and version updates shouldn't be that frequent.

I don't know how to enable it. It isn't mentioned on the config screen, though not very much is.

How much ricing have you done of the default config? Lazy loading of plugins is enabled by default— you shouldn't have to do anything. LazyVim handles lazy loading automatically; you don't need to manually configure anything. It should look like this:

    -- lazy.nvim configuration example
    require('lazy').setup({
      defaults = {
        lazy = true, -- default to lazy loading
        -- other default options
      },
      plugins = {
        { 'neovim/nvim-lspconfig' },
        { 'hrsh7th/nvim-cmp' },
        -- ... other plugins
      }
    })