Ad 1) biblatex-ieee sets maxcitenames = 3, minnames = 3, in the .cbx and maxnames = 999, minnames = 3, in the .bbx. This results in maxcitenames=3, maxbibnames=999, mincitenames=3, minbibnames=3.
The min<names> counter must always be less or equal to the max<names> counter, so maxnames=1, conflicts with the min settings of 3. So you will have to change both maxcitenames and mincitenames.
You would use
maxcitenames=2,
mincitenames=1,
to change the citations only.
In the discussion below it emerged that you want to change (primarily) the behaviour in the bibliography, so
maxnames=2,
minnames=1,
should give you what you want. As that changes both maxcitenames (for citations) and maxbibnames (for the bibliography) and mincitenames (for citations) and minbibnames (for the bibliography) respectively.
Ad 2) natbib=true enables the natbib compatibility mode. You can then use \citep as alias for \parencite, \citet for \textcite. Additionally some of natbib's cite alias feature is implemented. Note that the starred versions of the cite commands differ between standard biblatex and natbib mode. (See also §3.8.9 natbib Compatibility Commands of the biblatex documentation and Is there a disadvantage to using natbib=true with biblatex?.)
If you don't need \citet as alias for \textcite, you probably don't need natbib=true.
Ad 3) What is the "best" style is a purely subjective choice. If you happen to write for/under the supervision of anybody (that includes thesis instructors, publishers, journals, ...), the best style is what they tell you to use. If you don't have any instructions on style use what you like best or what seems to be the norm in your field.
The MWE
\documentclass{article}
\usepackage[backend=biber,
sorting=none,
doi=false,
isbn=false,
url=true,
maxcitenames=2,
mincitenames=1,
style=ieee,]{biblatex}
\addbibresource{biblatex-examples.bib}
\begin{document}
\cite{sigfridsson} \textcite{sigfridsson}
\textcite{aksin,baez/article,worman}
\printbibliography
\end{document}
then gives
[1] Sigfridsson and Ryde [1]
Aksın et al. [2], Baez and Lauda [3], and Worman [4]
natbib, part Q2. I asked Q3, if anyone has personal opinion. – Dr.PB Sep 04 '16 at 05:24biblatexquestions an MWE can really be useful to others because they can test their solutions. That way you can make sure that all the necessary information to answer the question is on the table. – moewe Sep 04 '16 at 05:40biblatex-ieeeis to follow the rules of the IEEE as far as possible. I'd normally say don't adjust this: the entire point of following a publisher style is that it's a norm in an area! – Joseph Wright Sep 04 '16 at 07:10