Could you correct these sentences, please)

1. You have a tight-knit ally. - Yes, I feel like my spouse is my shield (you could say "is like a shield for me" but Americans tend to use metaphors more often than similes when speaking passionately, as in the case of a spouse.). He is very mindful.

2. perfect

3.I foretaste that you will be disappointed because you live in a vivid daydream. (No American would ever use the word foretaste. They would be confused if you used it. We would simply say, "I think that," or... if you were a fortune teller, "I foretell that..." Think would be the most common usage, however.)

4. I assure you that it is a habitable place. I heard any sounds and saw some footprints on the ground.

5. The earthquake broke all her possessions. You never have any assurances if you are living in such region.

6. Now it is a craze to wear a beard. Yes, fads come and go.

7. You always like to rejoice, although I know that there is an innermost sadness within you.

8. You are compassionate and selfless. In comparison, I am an absolutely insensitive and uncaring person.

9. It is a very labor-intensive process to create something worthwhile. (hyphenation is rarely needed grammatically, and is more often a stylistic interpretation. You should look up hyphenation rules to understand when and where you are edging out ambiguities, etc.)

10. Ann's former work was outrageous. There was not any possibility to grow and improve her mastery. Her perseverance was completely futile. (An American would say, "Ann's previous employer was outrageous. There was no room to grow and improve her skills. Her perseverance was completely futile." However, your sentence was completely intelligible, but it would sound like you were a foreigner.)

Could you correct these sentences, please)

9. It is a very labour-intensive process to create something worthwhile.
10. Ann's former work was outrageous. There was not any possibility to grow and improve her mastery. Her perseverance was completely futile. (Ann's former job was outrageous. There were no possibilities to advance and learn new skills.)

4. I assure you that it is habitable. This is also fine, using 'place' means the 'a' is required.

In the negative: "I didn't hear any sounds" or "I heard no sounds" or even "I heard nothing".

".. on the ground" can be presumed unless you saw footprints somewhere else!
It has been a while since I read one of your posts Yljaha but you seem to be still improving.

The alternative on 7 was in case you needed to use "innermost".

Any questions, just ask!