The forum account is separate from your ProFantasy account, so your credentials will probably work fine over at the registered user's page. If not, you'll have to contact ProFantasy support to fix that.

Note that of course, there is always a chance that your installation is messed up, but in 99% of cases, it is only a map issue (map set up to use wrong style, or style have been manually changed, or map style simply doesn't have those tools) rather than something being wrong with the CC3+ install.

Note that newer products won't neccessarily say this at all, because they are ONLY compatible with CC3+, and nothing else. Every ProFantasy product have been compatible with CC3+ for several years now. However, if you own some very old products from the CC2-era, some of them require a paid upgrade to the new version, but since you said you got the CC3+ bundle deal, everything in that bundle would have been compatible from day 1.

Everything in the bundle is compatible. Just make sure that when downloading the installers from your profantasy registred user page that you grab the ones that are labeled as being for CC3+ if there are more than one to choose from.

Also, make sure to (re-)install the latest CC3+ update as the last thing you do, as that do some fixing up.

These messages are due to a library file being accidentally copied by an installer into the installation directory. Please close down CC3+ and delete cc2per.dll from your installation directory (c:\program files(x86)\ProFantasy\CC3Plus)

These are normal errors when you are using a style that doesn't have certain tools. Not all styles have all tools. This isn't normally an installation error. For example, dungeon styles doesn't have landmass tools. It can also happen if the style of your map has been changed, which can be changed from :CC2PRESETS:

Use :CC2BREAK: to remove the parts of them you don't need. Remember you can use the :CC2MODINT: modifier to get the exact points where they cross.

Breaking a polygon WILL turn it into a line, but just continue working with the line until it is correct, and then you can turn it pack into a poly when done by right clicking :CC2EXPLODE: and picking Path to Poly. If you removed a corner during the process (which you will likely do, you'll need to add in a new one using :CC2INSNODE: to avoid a missing portion of the poly in the corner.

To make the two polys line up exactly against the border of one of them, start by trimming the light poly to the points where it meets the dark one, then make a copy of the dark one, trim it down to just that path segment where they share a border, and use Combine Paths to merge that with the light one, this will result in them both having a border in that space.

Note that it might also be simpler to delete the lighter poly, and assuming it is drawn using a drawing tool, simply use the trace feature of the drawing tool to follow along the edge of the darker poly.

Edit: Beaten by a little mouse, but with a very different approach.

That message shows up because there aren't any wall tools in that style, nothing wrong with your installation.

The forlorn cottage style is a very limited style, and works best when used along with the Dungeons of Schley style, in which it is fully integrated.

If you click the :CC2DRAWTOOLS: button and select SS4 Dungeons of Schley as the style, you can access the full set of tools. The choice is remembered for the rest of the session, so you can use buttons like the wall button after doing that. (Note that this works between these two styles because they are integrated into each other, it won't work with other styles without also first importing the fills from the other style.)

For all practical purposes, yes.

As far as I know, no, it can't be automated. There isn't a macro-version of this command

This button is a relic from the time before styles, where you only had a single "set" of symbols. The catalog buttons are meant to load the catalogs belonging to the current active style, and no styles come with a simple catalog, so it is basically useless (and confusing) on modern installs. Unless you hard-code it to the old simple catalog, it is going to just display an empty catalog list most of the time. If a style does define a simple catalog (The main DD3 style actually does this for legacy reasons, put it is just a pointer to the old catalog, and not really a DD3-version of it) you can easily find it by clicking the :CC2SYMICOND: button yo get all catalogs defined for the current stylke.