mold earth does a 5' cube in a couple of seconds. what kind of shovel are you using where that's a small improvement?

any time you have a few minutes available to set up a battlefield, mold earth lets you do a massive amount of work. need to build some fortifications quickly? empty a 5'cube and place the earth right next to it and you have a trench and a short wall. it's usefulness in the middle of a pitched battle is relatively limited. it's usefulness in preparing for a pitched battle is massive.

mage hand is useful in a lot of situations that come up fairly often. every spell is "situational", purple is for ones where the situation is rare. "i need to move something and either am unable or unwilling to use my hand to do it" is not very uncommon for an adventurer, nor is "i would like to move something from a distance". we're talking about a game where a 10' pole is considered vital adventuring gear to some people.

as to careful not impacting the value of spells, i have to disagree. if your party has melee warriors (and most parties do), there is a gigantic difference between creating a zone that nobody should go into vs creating a zone that no enemy should go into. there is likewise a substantial difference between debilitating status effects that only hit enemies vs debilitating status effects that hit anyone.

it's the difference between darkness in a regular party (maybe one person can see through magical darkness some way or another) vs darkness in a party where everyone has a 2 warlock splash and devi's sight. the former isn't useless by any means, but the latter is so much better it isn't even a close comparison. in such a party, darkness goes from being roughly equivalent to a purple spell to being at least dark blue, probably even sky blue (seriously, if you turn down that buff you must have a very compelling reason).

some spells just get a heck of a lot better with the right metamagic, to a point where it isn't even comparable in value. suggestion goes from being something you can only use in private areas when the subject has no guards, to being a spell you can use any time you're dealing with a person who has something you want and doesn't want to give it up (provided they're not immune to suggestion somehow) if you have subtle spell. huge difference.

your metamagic selections *absolutely* should have a major impact on your spell selections. pretty much the only reason not to take any other spellcaster is because you want to combine specific metamagic abilities with specific spells. outside of metamagic, the sorcerer has *nothing* worth looking at. no interesting class features. even their archetypes tend to be pretty lackluster (storm sorcerer has a danged nice ability at 18, but it isn't worth 18 levels of being a much worse version of a wizard, which is basicalyl what you are if you aren't using your metamagic wisely).