What are some struggles and difficulties in creating a good literature review?

Why is it important to conduct a quality literature review? What are the essential components of a quality literature review? What are some struggles and difficulties in creating a good literature review?
Second Assingment is: How do theory and research influence each other? How do theory and research affect practice in nursing? Using your experience as a nurse, provide an example of how a theory or research affected patient care.
Third assignment:
Submit your Research Questions for Approval
What is a research proposal?
The purpose of the research proposal is to identify and formulate questions that arise from nursing practice and to design a research project to study the identified problem. The goal of a research proposal is to present and justify a research idea you have and to present the practical ways in which you think this research should be conducted. Research proposals contain extensive literature reviews and must provide persuasive evidence that there is a need for the proposed research study. In addition to providing rationale for the proposed research, a proposal describes detailed methodology for conducting the research consistent with requirements of the professional or academic field and a statement on anticipated outcomes and/or benefits derived from the study.
Directions:
You will be required to write a research proposal to be submitted in week 7. This may be either a qualitative or quantitative research proposal. The proposal should be a 6?10 pages plus appendices, cover page, and reference page. In week 8, you will present your proposal to your classmates via video presentation.
This week, you will submit a topic for your research proposal and presentation as well as the research questions you will be utilizing for your proposal and presentation. Your instructor must approve your research questions and topic for your proposal.
Submit your journal assignment and include the following:
Research topic for the proposal and presentation
Research questions for the proposal and presentation
Note: Once approved, any changes to your topic or research questions should be approved by your instructor.