1897 Assessment
Abstract If we consider the "Introduction" to be the abstract, then it is a reasonable start, but will benefit from greater focus.  The first three sentences are too general to have much value.  Indeed, only the final sentence is directly about this project.  So, try to rewrite, or write from scratch, an abstract that really focuses on the research project (although it may mention wider issues to provide context).  In particular, include the research question (ideally phrased in one sentence with a question mark at the end) in the abstract. 
Research Question The  research question is clear and focused, but it should make its first appearance before the literature review (so we know what we are looking for in the review).
Literature Review  The literature review has good breadth and is written clearly.  However, it is a bit too serially presented.  It would be better with a starting paragraph that introduces what the review will cover, that is the main questions and arguments.  Doing this could provide some ideas about the organization of the material and having it there will help readers.
Data The data set discussed in the proposal sounds plausible.  However, at this time there appear to be too many unknowns about this data to have confidence that it will serve the project effectively.  These unknowns should be resolved quickly, before investing much more time in the expectation that this data will support the research.

To begin, yes, there must be a codebook in order to use the data.  Guessing, however apparently accurate, is not really an acceptable strategy.  It is necessary to know the exact wording of every question and all coding.

The article cited as source of the data does not appear to provide information on the sampling?  This information should appear in the proposal.

Special note: The entire section on data was mostly lifted directly from the Strobe article, without identifying it as a series of quotations (and, no, the citations at the ends of paragraphs do not meet this requirement).  As such, this constitutes plagiarism.  As this is a preliminary draft, we will let this go, but we do not want to see any signs of this in the future.
Causal Interpretations It is not what theoretical (or psychological) logic leads to the principal hypothesis, although the proposal shows how it reflects past findings.  Logically, it seems backwards in part.  On the face of it, it would make more sense for those with greater fear of becoming victims, but who do not themselves own guns, to support gun control, not oppose it.  Similarly, if you think you will become a victim, shouldn't you prefer that "criminals" do not have guns with which to threaten and shoot you?  It the opposite is expected to be true, we could use some explanation why that would be. 

Note one implication of this thought.  The proper control for gun ownership may not be whether the respondent owns a gun, but whether someone in their household owns a gun.  I don't know what has been used in past research.  It is even possible that a desirable control might be whether anyone with whom the respondent is closely connected by kinship or friendship owns a gun for protection.  For it could be that the perception of guns mainly as a potential threat rather than as protection depends on gun ownership being absent from an individual's social world.
Research Value The references to the potential social value of the research are okay, but the defense of the research's value should stress how the proposed research will contribute to the existing literature on related issues.
Timetable The provisional schedule is okay, except that depends on the data being up to the task and not producing unanticipated problems.
Citations & Biblio The reference structure seems fine (excepting the inappropriate copied materials in the data section).
Quality of writing The writing is ok, but there are numerous grammatical errors and awkward sentence constructions that detract from the overall writing quality.  Proofread carefully for the final draft. 
   
Priorities for Revising for Final Draft The first things you want to get done are to get the information needed to decide the worth of the data set and to rewrite the data section.  Secondly, you should work on the causal analysis, which appears to be underdeveloped.  If you can get these worked out, the proposal looks like it should lead to a good project.
Miscellaneous Notes