I’m in the hospital and on many medications and I thought you were asking if you could remove part of the spider without harming the spider.

I am going to assume you have a cellar spider. Removing part of the web isn't going to directly harm them. They don't recycle their web so you aren't even removing nutrients from them.

The only way it's going to affect them is by reducing their chances of catching prey. Cellar spiders don't have a sticky web and rather rely on prey brushing up against their web, then rushing there and killing it with a bite. So you are reducing the area they are covering.

They also usually just gradually increase the size of their web. So it's unlikely it will try to rebuild everything you removed at once. Meaning it's not going to waste too much energy.

You’re a true spider bro

Unlike spiders, Daddy Longlegs don't spin webs because they do not produce silk. Daddy Long Legs actually have only two eyes unlike spiders who have eight. Another difference is that Daddy Longlegs are not venomous. They do not have fangs or venom glands. - from Google.

Yes. The web isn’t a horcrux or anything for the spider. I can build new webs.

I don't think it's an issue to remove part of the web. I've got spiders outside that tend to keep blocking the entryway and I have to destroy parts that get in the way of the path. They're usually back within a day or so.

For a more solid answer, the link below describes moving spiders entirely by relocating part of the web with the spider. I think trimming the web is going to be less stressful than that.

https://askentomologists.com/2015/10/11/how-do-i-relocate-insects-and-spiders/

I don't know anything about daddy long legs, but I'd assume it's okay as long as you don't try and do it when it's in the web.

If it needs a web to live its life then it must be able to account for damage. Whether that means it repairs your damage or it decides another location would be best, it should be able to accommodate.