Good evening all[smile].
I am not really a Wiccan dear lady, and my methods can be rather unorthodox at times, but if it pleases yea I shall answer your questions to the best of my abilities.
1.Tools like the Athame are only as magical as you want them to be, and they are great for helping you focus your energy when you're doing things like casting the invisible boundary of your circle[When I do this I like to imagine shooting a beam of light out of my Athame, like a blue laser.]and such, but ritual tools like this are
just props. The power/magick is of the Gods, invested in you. You could do the very same action using naught but your pinky finger, or your mind if you wished. Intent, imagination, and reverence for the Divine is everything. I like tools, objects, costumes, and such because they but me in that "special mood"...but they are still,
only props.
2.I don't think so. Religious spells, well, perhaps so, as the circle creates a special place to help link you to the Divine[Calling Corners, Invoking the Goddess, etc.etc.] or raise energy[Cone of Power?], but for anything else it's probably just a matter of your personal preference. I cast all kinds of spells alllllll the time without creating/using a circle. If I'm outside, and I'm standing upon the grass, and the Sun or Moon is shining upon my up-turned face, and the wind is in my hair, then by golly as far as I'm concerned I'm ALREADY physically connected to the God and Goddess sufficiently for any spells I might wish to cast.
Do you think that a Christian's prayers are only effective/heard by God if they are prayed within the confines of a Church?
Nonsense! And it can work the same way for you, too.
3.What MoonTraveler said. Also, see above.
4.Ah, family dynamics, eh? Bummer that. You are very young, and have to follow the rules of your parents. Do you know why she is opposed to Wicca and Magick? Learn what her reasons are if you don't already know. And what do you mean by "opposed", anyway? Is she scared to death that her little girl is "dabbling in devil worship"

, OR...is she just restricting your freedom of burning dozens of candles in your bedroom[grins]? Beeeeee honest. I need to know more about what's going on between the two of you before I offer you better advice on this issue.
5. Pfffffffft! Heck no!
Recall what I said about a Christian's prayers near the end of my answer #2? To use Christians/Christianity as an example again[because to me, a prayer is just a magickal spell by another name...], that would be like saying that prayers are only heard by God....IF you're a Monk or a Priest. Ah, horsefeathers!
If you believe that Deities love and care about you, then you may as well also believe that they will allow you to preform an act of magick whether you're in a coven all dolled up in silver jewelry, fancy robes, as a member of some huge exclusive coven, or as a barefoot, rag-wearing peasant living all alone in a hut in the wilderness. Go hunt for and read some of Scott Cunningham's books, like his "Guide for The Solitary Practitioner".

I hope that some of this was of some help to you dear lady, and I look forward to hearing back from you in the future[smile].