Lately, I've begun working on duplicating a 16th century French Bible with XeTeX:
https://github.com/raphink/geneve_1564
It features image lettrine and OTF features using XeTeX, specifically the advanced features from the open-source EB Garamond font, some of which were implemented specifically for this project (thanks to Georg Duffner's great reactivity).
The project is still a work in progress (the marginpars can be improved) and only features one page so far.
Edit:
After reworking a few details, I ordered a printed copy recently, using zazzle:
Edit on 2015/07/07:
Fixed some details in the first page, and added a second page, featuring the EB Garamond Initials font.
One other option is to invest some time in mastering any decent text editor or latex-specific editor. Either of two will certainly solve your problem with images.
Having math typed in LaTeX is the most portable solution. I find it easier to deal with math when using unicode-math.sty in xelatex.
Since you already know beamer I think it is your best bet. Inkscape or Libreoffice impress has a crippled and unmaintainable support for math, IMHO.
Edit:
I'm using Emacs. Its LaTeX modes AUCTeX, RefTeX are great already, but you may want to write some extra things to speed-up workflow.
Drag and drop images
One can use ido-completion-read to insert images. For this it is convenient to keep images in a separate folder. Here's an example TeX-doc tree:
doc/
├── img/
└── slides.tex
The following defun lets one choose an image with ido-completion:
(defun tex-image-from-./img (image)
"You are editing a TeX file. The images are in the ./img folder.
Call this defun to select the one to insert. Default image width is
0.45\\columnwidth. You can provide the width with C-u arg."
(interactive
(list
(replace-regexp-in-string
"^.+/img" "img"
(ido-read-file-name "Image file: " "./img"))))
(let (
scale
)
(if current-prefix-arg
(setq scale current-prefix-arg)
(setq scale "0.45"))
(insert (format
"\\includegraphics[width=%s\\columnwidth]{%s}"
scale image))))
This is a simple defun which might be further tweaked to match the desired behaviour.
For example one can easily write a defun which will ask for two images, and place them in columns.
As to an exact drag-and-drop behaviour -- one might use it to copy image to the ./img folder. For example evince allows one to drag-and-drop given raster image from a pdf file to file manager.
This has an additional benefit of keeping things organized: having all images in the latex doc folder will come handy when you set up to write a book.
Templates
For examples the following defun insert template for a slide:
(defun tex-insert-beamer-slide-template ()
(interactive)
(insert "\\frame{
\\frametitle{}\n\n}")
(search-backward "frametitle{}")
(forward-char 11))
This is just a basic defun, but arbitly complex scripts are not far away.
One can easily template math inputs (for example system of equations template) or whatever. Templates allow to reduce the tex-code to be typed (and looked-up), and thus speed-up workflow.
Custom build script
In order to speed up the workflow one should really build LaTeX doc with a single command. latexmk might be fine, but personally I prefer a simple bash script. You can make a complex bash script for all cases or a single bash script for each document (to be kept in the doc's folder, smth like make.bash).
With custom build script one can easily insert svg images in LaTeX. Just make the build script convert file.svg to file.pdf if the former is newer then the later, or the later doesn't exist at all (enen better: one can automate the export to latex inkscape functionality to get the same fonts on the svg image as in the latex doc).
Edit 2:
Images in the Internet
If a desired image is in the internet, one can copy it's URL and give the URL to a small elisp defun which would download it in the ./img and insert with the code similar to posted above to one's tex file. The image's URL might be copied fast with extensions Pentadactyl for Firefox or cVim for Chrome. You might also like to switch between browser and emacs with a hotkey. So three keystrokes overall: copy URL, switch to emacs, call the defun.
Best Answer
LaTeX beamer
I've written a short introduction to LaTeX beamer.
Here are some better themes that the standard ones (thanks dcmst).
English language course
Tutorial for programming
ICPC Presentation