Question re updating android apps via Play Store

[intrepidity]

There are several apps that are hard-baked into my phone but that I don't want, don't use, but can't delete.

I typically do manual updating, and so these apps sit there, begging to update, but I ignore them.

Is there any risk there?

The main issue involves space. Seems every update is at least 5mb; 20 apps that need frequent updates can rapidly chew through an older phone's memory.

A second issue about space: often, there will be space avail (internal, not SD card), far more than an app or update "says" is required; yet still I get the "not enough space" routine. What gives?