Do you use client files from version 7.0.104.x or newer? Then it won't work because with New Legacy beta patch gumps got additional encoding and that wasn't implemented in ultima sdk that gump editor is using
Which download? :) What malware? Ced+ maybe had some flaws but I never seen a copy with malware. Most of the time it's a false positive because it's not signed binary.
You can find link in POL repository GitHub - polserver/polserver: PenUltima Online (POL) is a MMO server, compatible with most Ultima Online clients. POL is customizable via configuration files and has its own scripting language (eScript).
In version 7.0.104.x and newer client versions there is new format for gumps and clilocs and uofiddler doesn't support that yet. Last working version is 7.0.103.x. I don't know yet when we will have full support for gumps and clilocs. Right now only clilocs are readable.
Just enable uopacker plugin in uofiddler and use uopacker tab and then choose correct file type and convert it? Still depends on uo files version as latest are not supported and may fail.
If you import them and save as uop then why not? Kinda depends on uo version as there is no packer that is using bwt compression for clients 7.0.104.x and newer.
That's hardcoded in client so you either have to customize client or you can do some experiments with font files as it looks like regular ascii font. Changing font file will affect whole client not just this status gump.
It's not possible. Since movint to uop (mythic) patcher around version 7.0.20.x+ it always patches to latest. Your only option is someone making a copy and hosting it somewhere.
The gump logic is hardocded in the client so if you need to add something besides what is there already then you need to write/customize your own uo client. Editing clilocs or gump graphic won't help here.
Tiledata is a client flag set :D it has nothing to do with server. If you want to do something write a script. You can use tiledata on your server to be able to check some flags but that's it :D It's just a value,
It's probably because you try to compare .uop files and compare plugin only reads .mul so you'd need to unpack the mul first so you can point compare plugin to second file.