Sure! Below are the completed sentences along with explanations for each:

1) **Rita wasted a lot of money on DVDs.** 'I wish I **hadn't wasted** so much money on expensive DVDs!'
- **Explanation:** This sentence expresses regret about a past action. The use of "hadn't wasted" refers to a desire for a different past outcome.

2) **Rita thinks new jobs are difficult to find.** 'I wish new jobs **weren't** so difficult to find.'
- **Explanation:** This implies that Rita wishes the current situation (the difficulty of finding jobs) were different. "Weren't" is the past subjunctive of "to be," typically used to express wishes about the present.

3) **Rita thinks new jobs are difficult to find.** 'I wish new jobs **were** easier to find.'
- **Explanation:** Again, this expresses a wish about the present situation. The past subjunctive "were" indicates a desire for a current state (easier job availability).

4) **Rita can't go on holiday this summer.** 'I wish I **could go** on holiday.'
- **Explanation:** This sentence expresses a desire to be able to go on holiday, indicating that it is not possible for her right now. "Could go" is conditional, expressing ability.

5) **Rita doesn't have very good qualifications.** 'I wish I **had** better qualifications.'
- **Explanation:** Rita is expressing a wish for her current situation to be different. "Had" refers to a desire for better qualifications in her present or future.

6) **Rita has to do the washing up. She hates doing it.** 'I wish I **didn't have to** do the washing up.'
- **Explanation:** This expresses a wish for a different current situation (not having to do the washing up), suggesting that she would prefer not to be obligated to do it.

7) **Rita is sorry her family moved to the suburbs.** 'I wish we **hadn't moved** to the suburbs.'
- **Explanation:** This indicates regret about a past decision. The phrase "hadn't moved" reflects a desire for that past action to be different.

8) **Rita thinks she is very untidy.** 'I wish I **weren't** so untidy.'
- **Explanation:** This expresses a wish about her current state. "Weren't" is the past subjunctive used here to indicate that she wishes she was not as untidy as she perceives herself to be.

Overall, the sentences utilize the forms of "wish" to express regrets or desires for different present or past situations.