I am currently speedrunning this game. I am trying to find my own ways to do things fast, rather than looking up glitches and watching other speedruns. My PB is currently 4:05:17. What I want to know is, can I use stuff from DLC’s and LEC? I’m mainly just thinking about taking and selling Hal’s sword for some money.

That would save you around 30 seconds and its not overpowered or anything I would say yes altho I cannot really dictate what you can and can't do. if you submitted a Speedrun with the dlc on and used it to your advantage you would easily get your answer from the mods. I am a bit late to answer you tho