Table caption misplaced and no list of tables generated - latex

Question

I am writing an APA-style document in RMarkdown using Papaya package, which compiles into LaTeX, and then to pdf, by pandoc. I know a small amout of LaTeX, and I am not familiar with RMarkdown, and was asked to use it. So I have two problems here, and thank you in advance for any help. The problems might be related to Rmarkdown/Papaya, but they could also be purely LaTeX related, so even if you don't know about RMarkdown, you may still know something.
The first problem. I have the following table in my RMarkdown file,
\begin{center}
\begin{tabular}{| c | c | c | c | c | c | c |}
\hline
Model & Composability & Unboundness & Comm. & Sync. & Distribution & Mobility\\ \hline
$\pi$ & explicit & explicit & shared-mem & sync & NA & NA \\ \hline
Join & explicit & implicit & shared-mem & sync & implicit & implicit\\ \hline
Ambient & explicit & explicit & shared-mem & sync & explicit & explicit\\ \hline
Actor & NA & implicit & message-pass & async & implicit & implicit \\ \hline
\end{tabular}
\captionof{table}{Summary of Properties of Concurrency Models}\label{summary}
\end{center}
I was wondering how I can make the caption one-line and centered in the generated pdf file? It now spans two lines and is not centered (see this screenshot).
The second problem. I also would like to generate a list of tables after tables of contents. When I add \listoftables to the beginning part of the RMarkdown file together with other LaTeX command, \listoftables is missing from the generated .tex file, but the other commands shown below such as \newcommand are preserved in the .tex file.
```{r analysis-preferences}
# Seed for random number generation
set.seed(42)
knitr::opts_chunk$set(cache.extra = knitr::rand_seed)
```
\listoftables
\newcommand{\defeq}{\vcentcolon=}
\newcounter{equationset}
\newcommand{\equationset}[1]{% \equationset{<caption>}
\refstepcounter{equationset}% Step counter
\noindent\makebox[\linewidth]{Equation set~\theequationset: #1}}
\lstset{
basicstyle=\ttfamily,
mathescape
}
Then I notice there is an option at the beginning of the RMarkdown file
tablelist : no
and I change it to
tablelist : yes
but I get the following new compilation warning:
Warning message:
Package tocloft Warning: \#starttoc has already been redefined; tocloft bailing
out. on input line 1147.
The LaTeX packages that I included in the RMarkdown file are:
header-includes:
- \usepackage{amsmath}
- \usepackage{mathtools}
- \usepackage{listings}
- \usepackage{caption}