- No. FontCreator is not free. To use it for Commercial Use you need to purchase the Standard or Professional version.
- Whether it is permissible to edit an existing font or not depends on the license conditions of the font. If you search a little, you can find many fonts with GNU or SIL open licenses that permitted new versions to be derived from them as long as they are renamed. The license of the commercial fonts that are installed with Windows or other applications usually do not permit editing.
You will inevitably leaves some tracks by which the font’s lawful owners could prove that you edited their font. The chances of you being caught and prosecuted may be very slim, but since free and OpenSource Fonts are widely available, it makes no sense to modify commercial fonts.
License terms vary, so do read the small print carefully before investing your money in buying FontCreator and time editing the font:
The OFL allows the licensed fonts to be used, studied, modified and redistributed freely as long as they are not sold by themselves. The fonts, including any derivative works, can be bundled, embedded, redistributed and/or sold with any software provided that any reserved names are not used by derivative works. The fonts and derivatives, however, cannot be released under any other type of license. The requirement for fonts to remain under this license does not apply to any document created using the fonts or their derivatives.
Try uploading an image to What the Font? or ask on the Identify a Font Forum