Rather than "Ving" or "V"...

[z7655431]

According many different dictionaries and my book, the usage of "rather than" is really confusing. Sometimes, the verb after it takes a V-ing form, but occasionally it takes a V form. The following are what I collected. Could any native speakers to help me with them? Thanks!

1.
As the latte factor shows, you would be a lot better off if you saved or invested that money rather than spending it. (Ivy League English magazine)
→Is it also correct to use "spend" here?

2.
I think I'd like to stay at home this evening rather than go out. (Cambridge dictionary)
→Can I say "going" instead?

3.
Rather than go straight on to university why not get some work experience first? (Longman dictionary)
→Can I say "going" instead?

4.
Why didn't you ask for help, rather than trying to do it on your own? (Oxford dictionary)
→Can I say "try" instead?

 

[GoesStation]

I don't find the simple present natural in 1 and 4. I think the change of tense is the problem: they both begin with a proposition in the simple past which to my ears can only be followed by the gerund.

 

[TheParser]

NOT A TEACHER

Hello, Z:

I once found some advice that I am delighted to pass on to you.

"f you prefer to avoid the controversy [gerund or bare infinitive], use instead of with gerunds."

I guess that means if you are in doubt as to your first sentence, for example, then you can simply say "You would be a lot better off if you saved that money instead of spending it."

If you still want to use rather than, my source tells us that in "some cases ... rather than can only be followed by a gerund and not by a bare infinitive."

Maybe you can find my source in a good library. (I originally found it online, but I can't seem to find it again.) The book is The American Heritage Book of English Usage. A Practical and Authoritative Guide to Contemporary English (1996).