Tcorbet - You could download a PDF of the FZ150 Manual to study the details of what it actually does.
See Manual, Page 87, for the "Close-Up" mode, which would apply to your need for images of documents.
With any of the current bridge-zoom cameras, shooting in the 12-18" range doesn't require an add-on wide lens. That would be in the Standard Macro - not Super Macro, where offered - focusing range, in most.
The FZ150 calls this range "Close-Up", and the Canon SX40 combines Super and Std Macro into one function, range 0 inches - 1.6ft, which covers your 12-18" range.
For accurately imaging documents, particularly where they include diagrams, etc, being able to keep the camera at 90-degrees to the document is required. You could obtain a table tripod at modest cost. Do ensure that the legs spread widely enough to put the document between them, while stably holding the rotated-over camera.
Once set-up, you might use 'line-up' objects on the table, so you can just rapidly change pages in the document series. At that range, Manual Focus can be a help to ensure accuracy of fine detail. Use the Timer for shots, to avoid even the slight movements pressing the shutter when on a small light tripod can cause.
Most of the better current bridge-zooms can do these things without add-on lenses - but you can download Manuals to ensure that the functions do exactly suit your needs.
If you're doing scenes or portraits at the extreme wide-end of bridge-zooms, some lens distortion is expectable. They can over-correct in JPEG mode, and RAWs will usually need correcting in PP. The FZ150 has RAW ability - the SX40 will, with the CHDK 'hack'.
However, if you want fast-continuous, the SX40 does 2.4fps in standard mode, and 10.3fps in HQ mode, JPEGs.
The FZ150 does up to 12fps in full resolution, also 5.5fps with the AF focusing each shot, and does RAW, RAW+JPEG.
In RAW+JPEG it will do 11 shots at 5.5fps with AF per shot - or 11 shots at 12.5fps - focus on first frame only.
Certainly, folk will say that a bridge-zoom can't hold a candle to even a basic DSLR for image quality - and they're right. But for what you say you need to do - you couldn't do it - unless "very second-hand" - for even twice the price of a bridge-zoom. Body - close-up prime, 'std' prime for portraits and scenes - and a zoom for general-purpose.
Then you need to carry body and lenses around, change lenses, and maintain that equipment - all at maybe 3+ times the cost of a good bridge-zoom.... So the wallet - and what you need to do, and how - will tell you which way you need to go...