My thoughts about all this:
- guides already have an origin so there's no need to add other reference points on them; every operation done on a guide are intuitively expected to be done on it (e.g. aligning or distributing, something I would appreciate if added);
- I don't feel the need to have guides behave exactly as other objects: they are only guides, used for snapping or aligning other objects; if you want particular effects done on it, use lines (or does anyone want to blur a guide?);
- "convert guide to path" is simply creating a segment (a two point straight path) with its nodes laying somewhere on the guide, something really easy to do with already existing tools (and you can choose from where to where without having programmers guess what you want); also, this eliminates the problem of which styles to apply to border and fill (if a guide has only fill and no border, converting it to a segment with only fill and no border would lead to an invisible object!);
- I expect guides not being selected when I drag-select "normal" objects: I think at guides as something "stick to the paper" I'm drawing on so they are a reference; I wouldn't like having guides "mess with normal objects" (again, I would use segments if I need so); - the same applies to moving, rotating, grouping, and so on; I understand that being able to move (or scale) some objects together with the guides they are based on is interesting, but I'm not sure that this is what is always wanted so this could introduce difficoulties in other "normal" operations (like selecting some objects and not the underlying guides); what about introducing "construction lines", different than guides in exactly this aspect so they are managed as "normal" objects and follow them in transformations? - thinking of a grid that moves or scales or rotates if I (accidentally) drag-select it, simply frightens me;
- a way to easily select multiple guides (to move or delete them) must be added and it definitely must be different than for other objects (so you don't use it accidentally);
- having guides of different colours could create nice effects in my technical drawings... it's a pity they are not printed and that I don't have a colour laser printer... :) to say I don't feel this need; actually one interesting thing that could solve different problems without involving poor guides would be the possibility to have 0-thickness lines with a border (different than lines with no border), so they are always drawn with 1 pixel width depending on the device resolution (1 point if printed, 1 pixel on screen regardless the zoom level, etc...); I don't know if this is allowed by SVG specifications; they could be moved, aligned, rotated, scaled, jiust like normal objects as they would be normal objects;
- I don't want objects sticking to guides: what when I want to move a guide? would all objects I aligned on it follow me? Aaargh!
Please, let guides (and grids) rest in place.
Luca