1.术士升级可以拿已知低环换成已知高环吗？
可以。
Additionally, when you gain a level in this class, you can choose one of the warlock spells you know and replace it with another spell from the warlock spell list, which also must be of a level for which you have spell slots.
2.祈愿术效果“你让最多十个你能看见的生物获得对你选择的一种伤害类型的抗力”是永久的吗？
永久。但这样放许愿会有不良影响。The stress of casting this spell to produce any effect other than duplicating another spell weakens you. After enduring that stress, each time you cast a spell until you finish a long rest, you take 1d10 necrotic damage per level of that spell. This damage can’t be reduced or prevented in any way. In addition, your Strength drops to 3, if it isn’t 3 or lower already, for 2d4 days. For each of those days that you spend resting and doing nothing more than light activity, your remaining recovery time decreases by 2 days. Finally, there is a 33 percent chance that you are unable to cast wish ever again if you suffer this stress.
3.戏法里的等级是指人物等级还是职业等级？
人物等级。
4.属性书可以反复读吗？
RAW的话，可以。中间要等个一百年。 但我会说要问DM。而且PC属性上限是30。
The manual then loses its magic, but regains it in a century.
5.德鲁伊动物伙伴还有吗？
游侠有动物伙伴。德鲁伊没有。不过我只看PHB, UA有什么变体我就不知道了。
6.法师奇械师变体职业特性奇械精英“你也可以在使用药剂注法或卷轴注法时创造一件额外的药剂或额外的卷轴。”需要为额外的造物再付出代价吗？
原文或者link? 我猜是要的。
Superior Artificer
Starting at 10th level, you can create a second magic weapon, suit of armor, shield, or bundle of ammunition using your Infuse Weapons and Armor ability. Attempting to infuse a third item causes the oldest one to immediately lose its potency.
You can also create one additional potion or scroll using Infuse Potions or Infuse Scrolls.
并没有提到要再付出代价呀……
换个角度来想，本身奇械师就能用卷轴注法能力制造一张以上的卷轴（只要奥术恢复能力的环位够），如果要代价这里提到能额外创造又有什么意义呢（