Appropriate License for Available-Source, No-Unauthorized-Distribution

Question

I have a program (technically an addon to a program) whose code I want to be freely available for educational purposes or to create derivatives for personal use. However, I do NOT want to allow unregulated redistribution of either modified or unmodified code, whether for free or for profit.

However, I do want to allow the possibility of "pre-approved" derivative works - that is, the ability for a developer to request permission to distribute a derivative work (essentially an addon to an addon).

Finally, the licensing for the parent program (which I do not own) forbids selling my addon directly but does not forbid monetization via other means (such as adfly). I do not want to allow others to monetize my original code, but do want to allow them to monetize pre-approved derivative works.

Because of the rather nuanced nature of these requirements, and the fact it is NOT a free-distribution license like would be required for a "true" Open-Source license (as per the official definition), I do not know what license to use. Would creating my own be the best choice? Note that I do not have a lawyer nor do I have the resources to obtain one.

It appears on its face to be closest to a "visible source" license, but those do not seem to accommodate the "approved derivative work" aspect I want.

Here is the license as I have it so far. Is this a valid format and are these terms permitted to be used in this manner?

    /*******************************************************************************
    * @author Reika
    * 
    * This code is the property of and owned and copyrighted by Reika.
    * 
    * Any and all users are permitted to use the source for educational purposes, or to create derivative works
    * for private use only.
    * 
    * Unless given explicit written permission - electronic writing is acceptable - no user may redistribute this
    * source code nor any derivative works. These pre-approved works must prominently contain this copyright notice.
    * 
    * Additionally, no attempt may be made to achieve monetary gain from this code by anyone except the original author.
    * In the case of pre-approved derivative works, any monetary gains made will be shared between the original author
    * and the other developer(s), proportional to the ratio of derived to original code.
    * 
    * Finally, any and all displays, duplicates or derivatives of this code must be prominently marked as such, and must contain
    * attribution to the original author, including a link to the original source. Any attempts to claim credit for
    * this code will be treated as intentional theft.
    * 
    * Due to the Mojang and Minecraft Mod Terms of Service and Licensing Restrictions, compiled versions of this code
    * must be provided for free. However, with the exception of pre-approved derivative works, only the original author
    * may distribute compiled binary versions of this code.
    * 
    * Failure to comply with these restrictions is a violation of copyright law and will be dealt with accordingly.
    ******************************************************************************/

Answer 1

Licences are legal documents and thus you should ask a lawyer if your license covers what you want.

In my, non-lawyer, opinion, you try to cover too much in your license text. Most of it applies only to those persons that have gotten explicit permission from you to distribute the software, so you can just handle that in the 'contract' with which you give them the permission to distribute.

In my view, an appropriate license in your case could be:

/*********************
 * @author Reika
 * Copyright 2013
 *
 * All rights reserved.
 * Distribution of the software in any form is only allowed with
 * explicit, prior permission from the owner.
 *
 */

When people ask you for that permission, you are free to attach whatever conditions you want, such as attribution and that it can't be sold for money. You can even use different restrictions for different people.